Chemistry

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Active Exercise • When a strip of magnesium metal is placed in an iron(III) chloride solution, a magnesium chloride solution results and solid iron also forms. Develop the net ionic equation for the reaction
barium bromine ○ yes ○ no BaBr2 bromine sodium ○ yes ○ no
CHM-1C Measurement and Matter Predicting ionic compounds formed by two elements Decide whether each pair of elements in the table below will form an ionic compound. I space provided. element #1 element #2 Forms ionic compound? empirical formula of ionic compound --- --- --- --- fluorine oxygen yes no — iodine rubidium yes no oxygen magnesium yes no bromine lithium yes no
A reaction at -2.0°C evolves 574 mmol of carbon monoxide gas. Calculate the volume of carbon monoxide gas that is collected. You can assume the pressure in the room is exactly 1 atm. Be sure your answer has the correct number of significant digits.
Multiple Choice Question What is the final product of the reaction shown? A B C A B D
Consider the reaction below: CH4(g) + O2(g) → CO2(g) + 2 H2O(g) ΔH=-890.4 kJ Calculate the amount of heat (q) produced by the combustion of 7.74 g of methane. Include your sign indicating if heat is absorbed or released. kJ
Which postulate or theorem proves that these two triangles are congruent? ASA Congruence Postulate HL Congruence Theorem SAS Congruence Postulate
Give the net ionic equation for the reaction (if any) that occurs when aqueous solutions of H2SO4 and KOH are mixed. (A) H+(aq)+OH-(aq)+2 K+(aq)+SO42-(aq) → H2O(l)+K2SO4(s) B) H22+(aq)+OH-(aq) → H2(OH)2(l) C) H+(aq)+OH-(aq) → H2O(l) D) 2 K+(aq)+SO42-(aq) → K2SO4(s) E) No reaction occurs.
5.35 × 10^22 molecules O2 = LO2 STP
Which of the following alcohols undergoes dehydration most readily? (A) A (B) B (C) C (D) D (E) E
Problem Set #9 3. (5 pts.) Silver nitrate and sodium iodide react to make a precipitate. a. When 50.0 mL of 5.0 g / L AgNO3 is added to a coffee-cup calorimeter containing 50.0 mL of 5.0 g / L NaI, with both solutions at 25.0 degrees C, how many moles of AgI forms? Include a reaction equation! b. Find ΔHrnn for this reaction from the balanced net ionic equation. NOTE: The ΔHf° for AgI(s) is -62.38 kJ / mol; the ΔHf° for Ag+(aq) is -105.9 kJ / mol, and the ΔHf° for I^- is 55.94 kJ / mol. c. What is the ΔTsoln (assuming that volumes are additive and the solution has the density and specific heat capacity of water)?
Which of the following equals one atomic mass unit? A. one-twelth the mass of one carbon-12 atom B. the mass of one helium-4 atom c. the mass of one carbon-12 atom D. the mass of one electron
Use the molar bond enthalpy data in the table to estimate the value of ΔHrxn° for the equation CCl4(g) + 2 F2(g) → CF4(g) + 2 Cl2(g)
Construct the expression for Kc for the following reaction. 2 Ag(s) + Zn^2+(aq) ⇌ 2 Ag^+(aq) + Zn(s) Kc=
A chlorine (Cl) atom is adsorbed on a small patch of surface. This patch is known to contain 81 possible adsorption sites. The Cl atom has enough energy to move from site to site, so it could be on any one of them. Suppose a Br atom also becomes adsorbed onto the surface. Calculate the change in entropy. Round your answer to 2 significant digits, and be sure it has the correct unit symbol.
Entropy and Free Energy Calculating absolute entropy using the Boltzmann hypothesis An oxygen (O2) molecule is adsorbed onto a small patch of the surface of a catalyst. It's known that the molecule is adsorbed on 1 of 64 possible sites for adsorption. Calculate the entropy of this system. Round your answer to 3 significant digits, and be sure it has the correct unit symbol. An O2 molecule adsorbed at one site on a surface.
Complete the table below, using the diagram of an atom shown at right. Properties of subatomic particles name symbol charge (in multiples of e ) approximate mass (amu) location on diagram 0 1.0 A proton (choose one) (choose one) e^- (choose one) (choose one)
What four nitrogenous bases are found in RNA?
Which statement is true regarding the size of atoms and ions? A magnesium ion will be larger than a neutral magnesium atom. A magnesium ion will be smaller than a neutral magnesium atom. A magnesium ion will be the same size as a neutral magnesium atom.
What is the ground state electron configuration of molybdenum? [A r] 4 s^1 3 d^5 [K r] 5 s^2 4 d^4 [Kr] 5 s^1 4 d^5 [Kr] 4 d^6 [Ar] 4 s^2 3 d^4
Question 8 1 pts Assuming complete combustion, how many grams of butane (C4H10) would be required to consume 32.0 g O2 ? (Give the balanced chemical equation) 1.82 g 4.47 g 16.6 g 8.94 g 8.30 g
On a hot humid summer day, you leave your ice tea sitting outside while you take a dip in the pool. When you come back, you notice water droplets are now present on the outside of your glass. What process from the hydrologic cycle are you witnessing? o sublimation o condensation o precipitation
The processes at Orange County almost other plants than clean the water include microfiltration that strains out anything larger than 0.2 microns, removing almost all suspended solids, bacteria and protozoa. This process at Orange County and most other plants then clean the water include microfiltration that strains out anything larger than 0.2 microns, removing almost all suspended solids, bacteria and protozoa. "A zap with powerful ultraviolet light and a bit of hydrogen peroxide finishes the job," he said. "But after all that, 13 percent of the water say they would also use to be recycled into the purified water, according to recent study in the journal Environmental and Resource Economics." "A small minority of people are very offended by this and can't get it down or stop it because of psychological barriers," said the study's lead author.
19. A Lewis structure for the oxalate ion is shown here. Select the best predictions for the angles labeled A, an O-C-O angle and B, a C-C-O angle. (a) A=120° and B=120° (b) A=109.5° and B=109.5° (c) A=109.5° and B=120° (d) A=120° and B=109.5°
Write a net ionic equation for the reaction that occurs when aqueous solutions of hydrobromic acid and barium hydroxide are combined. (Use H^+ instead of H3O^+.)
Decide which intermolecular forces act between the molecules of each compound in the table below.
2 NaNO3 + PbO → Pb(NO3)2 + Na2 O What is the mole ratio between sodium nitrate and sodium oxide? 2 mol NaNO3 / [?] mol Na2 O Fill in the green blank.
The chemical equation shows how ammonia reacts with sulfuric acid to produce ammonium sulfate. 2 NH3(aq) + H2SO4(aq) → (NH4)2SO4(aq) How many grams of ammonium sulfate can be produced if 60.0 mol of sulfuric acid react with an excess of ammonia 1,020 g 3,970 g 5,890 g 7,930 g
sulfurous acid → product name #1? product name #2?
Your instructor added question feedback to this assessment Assignment Content Question 1 Consider the following Lewis structure: H-O=N=O How many valence electrons are present in the entire structure: 24 How many bonding pairs of electrons are in the entire structure: 5 How many lone pairs of electrons are in the entire structure: 9 Feedback Valence electrons are the electrons that each atom is either sharing with other atoms or holding as lone pairs. The number of valence electrons in the structure can be found by counting the numbers of dots and lines in the structure. Each line represents a pair of shared electrons and each dot represents one lone electron. A bonding pair of electrons is represented as a single line. A lone pair (nonbonding pair) of electrons is represented as a pair of dots.
What is the hybridization of the central atom in the (PO2^3-) anion?
Describe how you would construct a 90% confidence interval to estimate the population mean age for students at your school. Choose the correct answer below. A. Take a sample of at least 30 student ages and find x̄. Verify that σ is known and the sample is random. Find the critical value z0.05 to calculate the left and find the critical value z0.95 to calculate the right endpoint of the confidence interval. B. Take a sample of at least 30 student ages and find x̄. Verify that σ is known and the sample is random. Find the critical value z0.90 and use it to find the margin of error E. Then find the left and right endpoints of the confidence interval. C. Take a sample of at least 100 student ages and find x̄. Verify that σ is known or the sample is random. Find the critical value z0.10 and use it to find the sampling error E. Then find the left and right endpoints of the confidence interval. D. Take a sample of at least two student ages and find x̄. Verify that σ is known or the sample is random. Find the critical value z0.05 to calculate the right and find the critical value z0.95 to calculate the left endpoint of the confidence interval.
A radioactive isotope has a half-life of about 9 years, which means that if it starts with 1 kg of this isotope, 0.5 kg will decay during the first 9 years. Determine how much will decay during the next 9 years.
SF₆ has a geometric structure. - tetrahedral - octahedral - trigonal planar - linear
Calculate the volume in liters of a 0.15 M potassium dichromate solution that contains 350 mmol of potassium dichromate (K2Cr2O7). Round your answer to 2 significant digits.
Determine whether each equation is balanced as written. Mg + H2 SO4 -> MgSO4 + H2 Balanced 2 HCl + Mg(OH)2 -> 2 H2 O + MgCl2 Not balanced AgNO3 + NaCl -> NaNO3 + AgCl Balanced H2 + O2 -> 2 H2 O choose... C6 H12 O6 + O2 -> 6 CO2 + 6 H2 O choose ... CH4 + O2 -> CO2 + H2 O Choose ...
Normal saline is a solution of aqueous sodium chloride with a concentration of 0.90 % (g / mL). Express this concentration in molarity. concentration: M
Homework 2 Question 15 of 18 (1 point) Question Attempt: 1 of 3 Give the correct name for the following compounds. Part 1 of 4 Cs2 SO4 Part 2 of 4 Mg(CH3 CO2)2
What is the density of Xe gas at 70°C and 2.50 atm?
A nurse is teaching a client who has Alzheimer's disease and their caregiver about memantine. Which of the following instructions should the nurse include? Increase fluid intake to improve renal excretion. Report memory loss or confusion. Watch for manifestations of liver impairment, such as jaundice and abdominal pain. Avoid taking over-the-counter antacids.
How many milliliters of the approximately 0.015 M copper(II) sulfate solution are needed to prepare 100.00 milliliters of a 0.00030 M copper(II) sulfate solution? mL
A college chemistry instructor thinks the use of embedded tutors will improve the success rate in introductory chemistry courses. The passing rate for introductory chemistry is 69%. During one semester, 200 students were enrolled in introductory chemistry courses with an embedded tutor. Of these 200 students, 153 passed the course. The instructor carried out a hypothesis test and found that the observed value of the test statistic was 2.29. The p-value associated with this test statistic is 0.0109. Explain the meaning of the p-value in this context. Based on this result, should the instructor believe the success rate has improved? State the hypotheses that were used for the test. Choose the correct answer below. A. H0: p<0.69 and Ha: p>0.69 B. H0: p=0.69 and H3: p<0.69 C. H0: p>0.69 and H3: p<0.69 D. H0: p=0.69 and Ha: p>0.69 E. H0: p=0.69 and Ha: p ≠ 0.69
Chemical Reactions Predicting the products of a combustion reaction Predict the products of the following reaction. If no reaction will occur, use the NO REACTION button. Be sure your chemical equation is balanced! (CH2)3(OH)2(l) + O2(g) →
A snack food manufacturer estimates that the variance of the number of grams of carbohydrates in servings of its tortilla chips is 1.25. A dietician is asked to test this claim and finds that a random sample of 24 servings has a variance of 1.27. At α=0.05, is there enough evidence to reject the manufacturer's claim? Assume the population is normally distributed. Complete parts (a) through (e) below. (a) Write the claim mathematically and identify H0 and Ha. A. H0: σ^2 ≥ 1.25 B. H0: σ^2 ≠ 1.25 Ha: σ^2<1.25 (Claim) Ha: σ^2=1.25 (Claim) C. H0: σ^2 ≤ 1.25 (Claim) D. Ha: σ^2>1.25 H0: σ^2=1.25 (Claim) Ha: σ^2 ≠ 1.25 (b) Find the critical value(s) and identify the rejection region(s).
Balance the chemical equation below using the smallest possible whole number stoichiometric coefficients. Ca3(PO4)2(s) + SiO2(s) + C(s) -> CaSiO3(s) + P4(s) + CO(g)
Calculate the solubility of Ag2CO3 in water at 25°C. You'll find Ksp data in the ALEKS Data tab. Round your answer to 2 significant digits.
How many milliliters of the approximately 0.14 M prepared copper(II) sulfate stock solution are needed to prepare 100.00 milliliters of a 0.014 M copper(II) sulfate solution?
Chapter 21 Nuclear Species Quiz (4th Edition) 20. The NMR spectrum of hydrogen does not contain information about phosphorous because of differences in: A. spin density B. relaxation times C. nuclear mass D. Larmor frequency
Consider the differences between ionic, nonpolar covalent, and covalent bonds for the following questions. Are the bonds in each of the following substances ionic, nonpolar covalent, or polar covalent? Select the single best answer for each substance. Substance Type of bond ------ P4 ionic nonpolar covalent polar covalent NaCl ionic nonpolar covalent polar covalent PF3 ionic nonpolar covalent polar covalent BCl3 ionic nonpolar covalent polar covalent NaBr ionic nonpolar covalent polar covalent SCl2 ionic nonpolar covalent polar covalent For those substances with polar covalent bonds (PF3, BCl3, SCl2), arrange them in order of increasing bond polarity.
Question 4 5 pts Use the following information to determine the standard enthalpy change when 1 mol of PbO(s) is formed from lead metal and oxygen gas. (report as a whole number, remember ( - ) sign if needed, no sign is needed if positive) PbO(s)+C(graphite) → Pb(s)+CO(g) ΔHρ=107 kJ 2 C (graphite)+O2(g) → 2 CO(g) ΔH°=-222 kJ
The half-life of radium-226 is 1600 years. Suppose we have a 26-mg sample. (a) Find the yearly growth factor a. (Round your answer to eight decimal places.) a= (b) Find an exponential model m(t)=C a^t for the mass remaining after t years. m(t)= (c) How much of the sample will remain after 3900 years? (Round your answer to two decimal places.) mg (d) After how long will only 18 mg of the sample remain? (Round your answer to the nearest year.) yr
Question 5 (1 point) Which of the following is a solution of the initial value problem y ln(y) dx + x dy = 0 y(e) = e Hint: ∫ 1/(t ln(t)) dt = ln(ln(t)) + K y = x e^(x-e) y = e^(x / e) y = e^(e / x) y = e^(x^2 / e^2) y = x e^(e-x)
Classify each species as a Lewis acid or a Lewis base. Lewis acid Lewis base Answer Bank BeCl2 SO3 NH3 Na+ O2-
Chapter 6 Homework Question 22 of 24 (1 point) I Question Attempt: 3 of Unlimited Raisha =22 Methanol (CH4O) is used as a fuel in race cars. Gaseous methanol burns in oxygen (O2) to form carbon dioxide, CO2, and water vapor, H2O. Part 1 of 6 Write a balanced equation for this equilibrium. Include all physical states of matter. 2 CH4O(g)+3 O2(g) ⇌ 2 CO2(g)+4 H2O(g) Part 2 of 6 Write the expression for the equilibrium constant for this reaction.
Consider the reaction below: 2 CO(g) + O2(g) ⇌ 2 CO2(g) If Kc is 2.24 × 10^22 at 1273.0°C, calculate Kp at the same temperature. (R= 0.08206 L · atm / mol · K.)
In a titration, the endpoint is the point at which the indicator changes color, the pH equals the pKa, moles of acid equals moles of base.
MISSED THIS? Read Section 10.3. You can click on the Review link to access the section in your eText. Use the Lewis model to determine the formula for the compound that forms from each pair of atoms. Sr and S Express your answer as a chemical formula.
The molecular geometry(shape) of BH3 is trigonal planar trigonal pyramidal tetrahedral linear
Write the electron configuration of an atom of the element highlighted in this outline of the Periodic Table: Hint: you do not need to know the name or symbol of the highlighted element! [Kr] 6s^2 5d^10 6p^6
element or compound type of solid formed force holding the solid together melting point of solid ------------ CH3Br ? ? ✓ Os ? ✓ ? Ar ? ✓ ? ? ? ✓
Predict the major organic product for each of the following reactions. Be sure to clearly indicate the proper stereochemical relationships between groups (if appropriate), and write the word "racemic" next to any compound that is formed as a racemic mixture.
Gas A was collected in a 1.312 L container at 356.18 K. The pressure inside the container was 790.91 torr. The molar mass of gas A is 110.75 g / mol. Recall that PV = nRT, R = 0.08206 L* atm /(mol* K), and 1 atm = 760 torr. How many grams of gas A were collected? SHOW ALL WORK
The complete hydrolysis of one mole of phosphatidylserine yields the components phosphate, serine, fatty acid and glycerol, in which of the following respective molar ratios? a) 2: 1: 1: 1 b) 1: 2: 1: 2 c) 1: 2: 1: 1 d) 1: 1: 2: 1
A reaction at -12.0°C evolves 862 mmol of carbon monoxide gas. Calculate the volume of carbon monoxide gas that is collected. You can assume the pressure in the room is exactly 1 atm. Be sure your answer has the correct number of significant digits.
Which of the following vitamins is fat soluble? vitamin B6 vitamin K vitamin C folic acid
The rate of a certain reaction is given by the following rate law: rate = k[H2]^2[NH3] Use this information to answer the questions below. What is the reaction order in H2? What is the reaction order in NH3? What is overall reaction order? At a certain concentration of H2 and NH3, the initial rate of reaction is 91.0 M / s. What would the initial rate of the reaction be if the concentration of H2 were doubled? Round your answer to 3 significant digits. The rate of the reaction is measured to be 0.330 M / s when [H2]=1.3 M and [NH3]=1.4 M. Calculate the value of the rate constant. Round your answer to 2 significant digits.
Does a chemical reaction happen during this movie? O yes O no If a chemical reaction does happen, write a balanced chemical equation for it.
What is the estimated legacy load of CO2 in the atmosphere? 100,000 gigatons 1,000 gigatons 100 gigatons 10,000 gigatons
Complete the table with the number of inner, outer, and valence electrons present in an atom of each element. Number of electrons Element Inner Outer Valence -------------------------------- Br Cs Cr Sr
La siguiente reacción tiene un 80% de rendimiento. Se obtienen 64[g] de MOH a partir de 116.9[9] de MX: 2 MX(ac) + 2 H2O(l) -> 2 MOH(ac) + 2 H2(g) + X2(g) a) Determine la identidad de M b) Determine la identidad de X y el volumen de X2 producido si la T=140[°C], P=85[kPa] y R=0.08206[atm L mol K]
Diamagnetic Paramagnetic Answer Bank B₂ N₂ F₂ O₂ C₂
A covalent bond holds two atoms near each other because Select the correct answer below: the two electrons that form the bond repel one another. the two electrons that form the bond are attracted to a single nucleus. the two electrons that form the bond are attracted to both nuclei. two nuclei of the atoms attract one another.
A geochemist in the field takes a 18.0 mL sample of water from a rock pool lined with crystals of a certain mineral compound X. He notes the temperature of the pool, 20 °C, and caps the sample carefully. Back in the lab, the geochemist filters the sample and then evaporates all the water under vacuum. Crystals of X are left behind. The researcher washes, dries and weighs the crystals. They weigh 1.4 g. Using only the information above, can you calculate the solubility of X in water at 20 °C? Yes If you said yes, calculate it. Be sure your answer has a unit symbol and the right number of significant digits.
Chemical properties of matter are based on how substances react.
The Silk Road primarily facilitated trade between: Asia and Africa Europe and Africa Asia and Europe North America and Asia
Write the symbol of the element from which this form is derived. Write the formula of the code that forms. The planar variance should be at least 4 for a 4-ion system below.
S = C - O S = C = O S - C = O A B C Formal Charge S C O
Part A Spell out the IUPAC name of the compound.
Identify the HOMO in the MO diagram of NO (shown below). A σ (2s orbitals) B σ (2pz orbitals) C π (2px and 2py) D π* (2px or 2py) E σ*(2pz)
Select ALL that apply: Which of the following are examples of mitigation strategies that enhance sinks of greenhouse gases? Select 2 correct answer(s) Scaling up direct air capture systems. Enhancing capturing methane produced by landfills instead of letting it vent into the atmosphere. Reducing dependency on fossil fuels and replacing energy needs with renewable energy sources. Adding more greenspaces to urban areas such as roof-top gardens or enhancing parks to include more native vegetation.
19. On the reaction coordinate diagram below, draw the curve for the same reaction taking place with the help of a catalyst. Additionally, show how you would determine the new energy of activation. (3 points)
Question 7 A 1 M H2SO4 will be used in preparing the sodium oxalate solution for titration in this experiment. What volume of 6 M H2SO4 is required to prepare 200 mL of 1 M H2SO4 solution. (A) 0.03333 mL (B) 1200 mL (C) 33.33 mL (D) 1.2 mL
Which of the following is true? The square root of 4 is a rational number and an integer. -6.133... is an irrational number. The square root of 3 is a rational number. 0 is neither a rational number nor an irrational number.
A recent commercial claimed, "Everyone is switching and saving at least 50 percent on their phone bill." Which type of faulty reasoning is this phone company using to attract new customers?
The following data represent the pH of rain for a random sample of 12 rain dates. A normal probability plot suggests the data could come from a population that is normally distributed. A boxplot indicates there are no outliers. Complete parts a) through d) below. 5.20 5.72 4.99 4.80 5.02 4.58 4.74 5.19 4.61 4.76 4.56 5.68 A. If repeated samples are taken, 95% of them will have a sample pH of rain water between and 1. B. There is a 95% probability that the true mean pH of rain water is between and 1. C. There is 95% confidence that the population mean pH of rain water is between 4.73 and 5.24. (c) Construct and interpret a 99% confidence interval for the mean pH of rainwater. Select the correct choice below and fill in the answer boxes to complete your choice. (Use ascending order. Round to two decimal places as needed.) A. There is a 99% probability that the true mean pH of rain water is between and . B. There is 99% confidence that the population mean pH of rain water is between 4.62 and 5.36. C. If repeated samples are taken, 99% of them will have a sample pH of rain water between and . (d) What happens to the interval as the level of confidence is changed? Explain why this is a logical result. As the level of confidence increases, the width of the interval This makes sense since the
The values listed below are waiting times (in minutes) of customers at the Jefferson Valley Bank, where customers enter a single waiting line that feeds three teller windows. Construct a 95% confidence interval for the population standard deviation of the waiting times. 7.77 .7 6.56 .66 .76 .87 .17 .37 .47 .7
A chemist prepares a solution of magnesium fluoride (MgF2) by weighing out 0.0122 g of magnesium fluoride into a 400 mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in g / L of the chemist's magnesium fluoride solution. Be sure your answer has the correct number of significant digits.
A 1.05 L solution was made by mixing 462 mL of hexane, which has a density of 0.66 g / mL, and 0.61 L of toluene, which has a density of 0.87 g / mL. Calculate the volume percent of hexane in this solution.
Fill in the Blank 0.5 points Consider a 0.00550 M weak acid solution with a percent ionization of 8.20%. Round each answer to TWO places past the decimal in scientific notation and for pH. Part A: What is the concentration of H+ (in M) at equilibrium? Part B: What is the Ka of this weak acid? Hint: Set up an ICE table, determine the value of 'x', then plug that 'x' value back into the equilibrium expressions in Ka. Part C: What is the pH of this solution?
Which pair of element and most common ionic charge is correct? Na / 1- C/6+ F/1+ Ba / 2+
What is the net ionic equation for each of the following reactions? Note: Reference the Solubility of ionic compounds in water table for additional information. Part 1 of 2 Al(s) + HCl(aq) → Part 2 of 2 AgNO3(aq) + H3PO4(aq) →
A chemistry student needs to standardize a fresh solution of sodium hydroxide. She carefully weighs out 210 mg of oxalic acid (H2C2O4), a diprotic acid that can be purchased inexpensively in high purity, and dissolves it in 250 mL of distilled water. The student then titrates the oxalic acid solution with her sodium hydroxide solution. When the titration reaches the equivalence point, the student finds she has used 102.4 mL of sodium hydroxide solution. Calculate the molarity of the student's sodium hydroxide solution. Be sure your answer has the correct number of significant digits.
What class of water pollution can reduce visibility underwater by clouding up the water, reducing photosynthesis?
Bromination of isobutane is a two-step reaction. Step 1 + Br . → + H-Br Step 2 Br-Br → + Br . Overall reaction Using the table of bond dissociation energies for A-B → A+B, calculate the enthalpy of each step and the enthalpy of the overall reaction. Bond broken ΔH, kJ / mol H-H 436 Br-Br 194 H-Br 366 (CH3)3C-H 400. (CH3)3C-Br 292
Consider these qualitative observations describing a reaction and then answer the following questions: "A spontaneous reaction occurs in a solution within a flask. Upon touching the flask, it feels hot and becomes progressively warmer as the reaction continues" - Is the flask a part of the system or a part of the surroundings? - From these qualitative observations or by deduction using the Gibbs Free Energy equation, can you infer anything about the ΔH of this reaction? - From these qualitative observations or by deduction using the Gibbs Free Energy equation, can you infer anything about the ΔS of this reaction?
Deducing valence electron configuration from trends in successive... The first five ionization energies ( IE1 through IE5 ) of a Period 3 element have the following pattern: Make a reasonable guess about which element this is. Enter its chemical symbol below.
Write the electron configuration for a magnesium cation with a charge of +2.
The Ka of benzoic acid is 6.46 x 10-5. Determine its buffer range
A police officer randomly selected 593 police records of larceny thefts. The accompanying data represent the number of offenses for various types of larceny thefts. (a) Construct a probability model for type of larceny theft. (b) Are purse-snatching larcenies unusual? (c) Are larcenies from buildings unusual? Complete the table below. Type of Larceny Theft Probability Pocket picking Purse snatching Shoplifting From motor vehicles Motor vehicle accessories Bicycles From buildings From coin-operated machines (Round to three decimal places as needed.)
Draw the electron configuration for a neutral atom of titanium.
CH4(g) + Cl2(g) → CHCl3(l) + HCl(g)
QUESTION 15 According to Henry's law, the amount of gas dissolved in a liquid depends on all of these factors except A. the temperature of the liquid. B. the molecular weight of the gas. C. the partial pressure of the gas. D. the solubility of the gas. E. the surface tension in centipoises. QUESTION 16 Ischemic hypoxia results from poor blood circulation, such as occurs with a failing heart. A. True B. False
A monatomic ion with a charge of +2 has an electronic configuration of 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6. This ion is a(n) What is the chemical symbol of the noble gas this ion is isoelectronic with? What is the formula of the ion?
Determine the mass of 3.68% Na2SO4 solution that contains 0.963 g of Na+. Be sure your answer has the correct number of significant figures. g solution × 10^
A student dissolves 13.3 g of lithium chloride (LiCl) in 250 g of water in a well-insulated open cup. She then observes the temperature of the water rise from 22.0°C to 32.8°C over the course of 6.5 minutes. Use this data, and any information you need from the ALEKS Data resource, to answer the questions below about this reaction: LiCl(s) -> Li^(+)(aq) + Cl^(-)(aq) You can make any reasonable assumptions about the physical properties of the solution. Be sure answers you calculate using measured data are rounded to the correct number of significant digits. Note for advanced students: it's possible the student did not do the experiment carefully, and the values you calculate may not be the same as the known and published values for this reaction. Is this reaction exothermic, endothermic, or neither? - exothermic O endothermic O neither If you said the reaction was exothermic or endothermic, calculate the amount of heat that was released or absorbed by the reaction in this case. square kJ Calculate the reaction enthalpy ΔH per mole of LiCl. square kJ/mol
What is the pH of a 0.0620 M solution of hydrocyanic acid, HCN(Ka=4.9 × 10^-10)?
A chemist working as a safety inspector finds an unmarked bottle in a lab cabinet. A note on the door of the cabinet says the cabinet is used to store bottles of carbon tetrachloride, ethanolamine, tetrahydrofuran, dimethyl sulfoxide, and diethylamine. The chemist plans to try to identify the unknown liquid by measuring the density and comparing to known densities. First, from his collection of Material Safety Data Sheets (MSDS), the chemist finds the following information: carbon tetrachloride 1.6 g/cm^3 ethanolamine 1.0 g/cm^3 tetrahydrofuran 0.89 g/cm^3 dimethyl sulfoxide 1.1 g/cm^3 diethylamine 0.71 g/cm^3 Next, the chemist measures the volume of the unknown liquid as 1.064 L and the mass of the unknown liquid as 751 g. Calculate the density of the liquid. Round your answer to 3 significant digits. Given the data above, is it possible to identify the liquid? If it is possible to identify the liquid, do so.
Which of the following properties does soap, an emulsifier, have that make it useful for washing dirt off one's hands with water? Soaps emulsifying action helps to dissolve grime into smaller particles. Soaps dual polar and nonpolar nature helps bond oil and water. Soaps acidity causes grime to precipitate into the water. Soaps rough texture physically scours grime off surfaces.
According to the equation (2 A(s) + 2 B(aq) → 2 C(aq) + 3 D(g)), if 5.870 grams of A fully reacted in 252.555 mL of B, what is the concentration, in M, of B? The molar mass of A is 64.859 g/mol.
Br H2S
In each of the following pairs of hydrocarbons, which one would you expect to have the higher boiling point? Part A pentane or butane
Three compounds that contain elements from Group 16 are SeO2 F2, SeOF2 and SeOCl2. Possible Lewis electron dot diagrams for the compounds are shown below. (c) Which structure, A, B, or C, minimizes the formal charges for each atom in SeO2 F2? Justify your choice.
How many carbon atoms are present in one mole of serotonin? C10 H12 N2 O 1.2 × 10^24 atoms 6.02 × 10^23 atoms 7.2 × 10^24 atoms 6.02 × 10^24 atoms
Which particle represents the size of the sulfide ion compared to the sulfur atom?
Which of these four elements is the most reactive metal?
In the space below, write the unabbreviated electron configurations of the following elements: 1) Nitrogen 2) Sodium 3) Iron 4) Bromine 5) Barium
Question 7 1 pts Which of the following is evidence that the K-Pg Mass Extinction was caused by a bolide? Chicxulub Crater Decreased sea levels Iridium found in layers of rock formed at the same time as the K-Pg boundary Stishovite found around the world
Mr. Emmer gave a test in his Chemistry class. The scores were normally distributed with a mean of 82 and a standard deviation of 4. A student is randomly chosen. What is the probability that the student scores a 70 or below? Use the formula for a z-score z=(x-μ)/σ where x is the given value, μ is the mean and σ is the standard deviation. Then refer to the chart on page 11 of the lesson to find the probability. a. 0013 b. 0179 c. 0668 d. 5000
Batteries convert the chemical energy of an oxidation-reduction reaction to electricity. True False
A particular reaction has a rate constant of 0.101 M^-1 s^-1 at 25°C and a rate constant of 0.332 M^-1 s^-1 at 45°C. Calculate the activation energy (Ea) for the reaction in kJ / mol. Enter your answer with no units.
QUESTION 17 Consider two traits in cattle: coat color and horn presence. The dominant allele R results in red coat, and the recessive allele r results in white coat. The dominant allele P results in polled (hornless), and the recessive allele p results in horned. Bull X inherited one chromosome with the R and P allele on it and the other chromosome with an r and a p on it. Bull X is then bred to a rrpp cow. The numbers below are the resulting offspring 380 offspring with Red coat, Polled 365 offspring with White coat, Horned 28 offspring with Red coat, Horned 32 offspring with White coat, Polled Calculate the recombination frequency between these genes. Based on this recombination frequency, how often will Bull X pass on the R and P alleles together? Convert your answer to percent form, but do not put the percent sign in your answer. Round to two decimal places. For example 24.44
Intermolecular forces are the interactions between molecules and are generally weaker than bonds within molecules. What type of forces occur between a cation and an anion?
The vicinal dihalide and the vinyl halide can be generated in one step from an appropriate alkene. a) True b) False
United Blood Services is a blood bank that serves more than 325 hospitals in 15 states. According to their website, a person with type O blood and a negative Rh factor (Rh-) can donate blood to any person with any blood type. Their data show that 42% of people have type O blood and 15% of people have Rh- factor; 43% of people have type O or Rh - factor. Enter decimal answers rounded to 4 places where possible. a. Find the probability that a person has both type O blood and the Rh-factor. b. Find the probability that a person does NOT have both type O blood and the Rh- factor.
Consider an experiment done by holding the amount of FeSO4 at 3.00 mL and varying the amount of o-phen solution. Sketch what the plot of Absorbance vs. mL o-phen would look like. (You do not need to show the exact values on the x and y axes, but your graph should accurately represent the shape that is to be expected). Label your axes.
For each atomic number below, fill in the table for the name of the element, the number of protons, and the number of electrons. Part 1 of 2 Atomic number 40 Element name: Zirconium Number of protons: 40 Number of electrons: 40 Part 2 of 2 Atomic number 65 Element name: Number of protons: Number of electrons:
Consider the following mechanism for the decomposition of dinitrogen monoxide: N2O(g) → N2(g) + O(g) N2O(g) + O(g) → N2(g) + O2(g) Write the chemical equation of the overall reaction: Are there any intermediates in this mechanism? If there are intermediates, write down their chemical formulas. Put a comma between each chemical formula, if there's more than one.
¿Qué concepto tomista se refiere a la idea de que Dios es la causa primera e inmutable de todo lo que existe? a. Cinco vías b. Principio de Suficiencia c. Causalidad eficiente d. Acto y Potencia
What average volume should the chemical engineer report? Be sure your answer has the correct number of significant digits.
Identify the role of protons in determining the element symbol: PART II: Symbol SCREEN 1. Using the Symbol readout box, figure out which particles affect each component of the atomic symbol and how the value of the numbers is determined. Their locations correspond to the example to the right of the table below. Position in symbol box Term to describe this information Particle used to determine this How the value is determined ---- a Element symbol protons # of p will identify the element b p+e c Atomic number d Protons, neutrons
Question 37 of 44 How many unpaired electrons are found in a ground state atom of Fe ?
Calculate the needed amount of reactant for the reaction described below by constructing a BCA table and determining the grams of F2 required. Complete Parts 1-2 before submitting your answer. P4(s) + 6 F2(g) → 4 PF3(g) A mixture of F2 and solid P4 produce 120.g of P3. Assume there are 1000. g of solid P4 available. Based on your knowledge of stoichiometry, set up the table below that represents 100% yield with the given reaction conditions.
A chemical engineer is studying the following reaction: BF3(aq) + NH3(aq) -> BF3NH3(aq) At the temperature the engineer picks, the equilibrium constant Kc for this reaction is 1.4. The engineer charges ("fills") three reaction vessels with boron trifluoride and ammonia, and lets the reaction begin. He then measures the composition of the mixture inside each vessel from time to time. His first set of measurements are shown in the table below. Predict the changes in the compositions the engineer should expect next time he measures the compositions. reaction vessel compound concentration expected change in concer entration A BF3 0.99 M O increase 0 decrease O (no change) A NH3 0.53 M increase decrease O (no change) A BF3NH3 0.76 M increase decrease (no change) B BF3 0.56 M increase decrease O (no change) B NH3 0.10 M O increase 0 decrease (no change) B BF3NH3 1.19 M increase decrease O (no change) C BF3 1.37 M increase decrease O (no change) C NH3 0.74 M increase decrease O (no change) C BF3NH3 1.46 M increase decrease (no change)
A legal provision known as the provides a "bounty" provision for whistleblowers whose actions result in a legal conviction. The monetary award may total as high as 30 percent of the amount collected for violations that exceed 1 million.
PHYSICAL PROPERTY 1. observed with senses 2. determined without destroying matter Identify the following as a chemical (C) or physical property (P) : 1. blue color 2. density 3. flammability (burns) 4. solubility (dissolves) 5. reacts with acid 6. supports combustion 7. sour taste 13. odor CHEMICAL PROPERTY 1. indicates how a substance reacts with something else 2. matter will be changed into a new substance after the reaction PHYSICAL CHANGE 8. melting point 9. reacts with water 10. hardness 11. boiling point 12. luster 14. reacts with air 1. a change in size, shape, or state 2. no new substance is formed CHEMICAL CHANGE 1. a change in the physical and chemical properties 2. a new substance is formed Identify the following as physical (P) or chemical (C) changes. 1. NaCl (Table Salt) dissolves in water. 2. Ag (Silver) tarnishes. 3. An apple is cut. 4. Heat changes H2O to steam. 5. Baking soda reacts to vinegar. 6. Fe (Iron) rusts. 7. Alcohol evaporates. 8. Ice melts. 9. Milk sours. 10. Sugar dissolves in water. 11. Wood rots. 12. Pancakes cook. 13. Grass grows. 14. A tire is inflated. 15. Food is digested. 16. Paper towel absorbs water.
A substance has a half-life of 4.044 minutes. If the initial amount of the substance was 140.8 grams, how many half-lives will have passed before the substance decays to 8.8 grams? half-lives What is the total time of decay? min
c) Propose a synthesis placing the appropriate substrate/reagent in the boxes below. The synthesis should produce the product as the major product. substrate
Consider the following reaction at 25.00 °C: Mg(OH)2(s) ⇌ Mg2+(aq) + 2 OH-(aq) Calculate ΔG^0 for the reaction. Be sure your answer has the correct number of significant digits.
Question 6 .a of 6 Examine the orbital diagram for the ground state electron configuration of sulfur. Choose the correct orbital diagram for the ground state electron configuration of sulfur.
The length of human pregnancies is approximately normal with mean μ=266 days and standard deviation σ=16 days. Complete parts (a) through (f). B. If 100 independent random samples of size n=14 pregnancies were obtained from this population, we would expect sample(s) to have a sample mean of 258 days or more. C. If 100 independent random samples of size n=14 pregnancies were obtained from this population, we would expect sample(s) to have a sample mean of 258 days or less. (d) What is the probability that a random sample of 29 pregnancies has a mean gestation period of 258 days or less? The probability that the mean of a random sample of 29 pregnancies is less than 258 days is approximately 0.0035 (Round to four decimal places as needed.) Interpret this probability. Select the correct choice below and fill in the answer box within your choice. (Round to the nearest integer as needed.) A. If 100 independent random samples of size n=29 pregnancies were obtained from this population, we would expect 0 sample(s) to have a sample mean of 258 days or less. B. If 100 independent random samples of size n=29 pregnancies were obtained from this population, we would expect sample(s) to have a sample mean of 258 days or more. C. If 100 independent random samples of size n=29 pregnancies were obtained from this population, we would expect sample(s) to have a sample mean of exactly 258 days. (e) What might you conclude if a random sample of 29 pregnancies resulted in a mean gestation period of 258 days or less? This result would be so the sample likely came from a population whose mean gestation period is 266 days.
Using the thermodynamic information in the ALEKS Data tab, calculate the standard reaction free energy of the following chemical rear Al2O3(s) + 3 H2(g) → 2 Al(s) + 3 H2O(g) Round your answer to zero decimal places. kJ
Chapter 15 Homework 22. Most barium compounds are very poisonous; however, barium sulfate is often administered internally as an aid in the X-ray examination of the lower intestinal tract (Figure 15.4). This use of BaSO4 is possible because of its low solubility. Calculate the molar solubility of BaSO4 and the mass of barium present in 1.00 L of water saturated with BaSO4.
How many grams of water are needed to react with 36.2 grams of Li2O? Given: Li2O + H2O → 2 LiOH 2.12 38.94 21.8 1.21 none of the above
How many of these hybrid orbitals are on each carbon atom? □ orbital(s)
Calculate the equilibrium constant from the standard free energy change. Using standard thermodynamic data, calculate the equilibrium constant at 298.15 K for the following reaction. N2(g) + 2 O2(g) -> 2 NO2(g) K =
Elemental sulfur exists in two crystalline forms, rhombic and monoclinic. From the following data, calculate the equilibrium temperature at which monoclinic sulfur and rhombic sulfur are in equilibrium. - Delta Hf°(kJ / mol) and S°(J / K mol): S (rhombic): 0, 31.880 S (monoclinic): 0.30, 32.546 450 K 200 K -200 K -450 K 0 K
Question 14 (5 points) Which of the following is the net ionic equation of the reaction BaCl2(aq) with H2SO4(aq) Ba2+ + 2 Cl+ + 2 H+ + SO42- = Ba2+ + SO42- + 2 H+ + 2 Cl- Ba2+ + 2 Cl + 2 H+ + SO42- = BaSO4(3) + 2 H+ + 2 Cl- Ba2+ + SO42- = BaSO4(s) BaCl2 + H2SO4 = BaSO4(3) + 2 HCl
f(x)=x^2-5x, g(x)=3x+1, and h(x)=(x-1)/x a) (g ∘ f)(x) b) (h ∘ g)(x) c) (f ∘ g)(x)
Does a liquid release energy or absorb energy when it changes into a gas? Into a solid?
Question 28 (1 point) A student ran the reaction below. They calculated a theoretical yield of HgCl2 to be 34.8 g. 2 KCl + Hg(NO3)2 --> HgCl2 + 2 KNO3 If the student actually collected 32.1 g after filtering and drying the precipitate, what is the percent yield for their experiment?
Within a decade of the Montreal Protocol, what did scientists see? The rate of ozone thinning slowed down and stopped, but it did not reverse. The rate of ozone thinning slowed down and then began to increase again. The rate of ozone thinning slowed down and began to reverse. The rate of ozone thinning increased exponentially.
Below is the Lewis structure of the nitrogen (N₂) molecule. : N ::: N : Count the number of bonding pairs and the number of lone pairs around the right nitrogen atom in this molecule. bonding pairs: lone pairs:
How many moles of nitrogen are in (2.5 times 10^-2) mole of quinine? Express your answer using two significant figures. (nmathrmN=) (square) moles
Classify this Fischer projection as a D- or L-enantiomer.
Which solvent are lipids most soluble in?
8 AM Wed Nov 6 www-awy.aleks.com Measurement and Matter Calculating mass density A chemist working as a safety inspector finds an unmarked bottle in a lab cabinet. A note on the door of the cabinet says the cabinet is used to store bottles of acetone, methyl acetate, ethanolamine, diethylamine, and dimethyl sulfoxide. The chemist plans to try to identify the unknown liquid by measuring its density and comparing to known densities. First, from her collection of Material Safety Data Sheets (MSDS), the chemist finds the following information: liquid density --- --- acetone 0.79 g/cm^3 methyl acetate 0.93 g/cm^3 ethanolamine 1.0 g/cm^3 diethylamine 0.71 g/cm^3 dimethyl sulfoxide 1.1 g/cm^3 Next, the chemist measures the volume of the unknown liquid as 0.685 L, and the mass of the unknown liquid as 483. g. Calculate the density of the liquid. Be sure your answer has the correct number of significant digits. Given the density, is it possible to identify the liquid? O yes O no If it is possible to identify the liquid, do so. acetone methyl acetate ethanolamine diethylamine dimethyl sulfoxide
Select the definition that best matches each term. Term a. Assets b. Common Stock c. Creditors d. Liability e. Retained Earnings f. Stockholders g. Stockholders' Equity
How many moles of ammonia would be required to react exactly with 0.366 moles of copper(II) oxide in the following chemical reaction? 2 NH3(g) + 3 CuO(s) → 3 Cu(s) + N2(g) + 3 H2O(g)
11) Which scientist found that "Chemical reactions occur when atoms are separated, joined, or rearranged:" A. Dalton C. Thomson B. Rutherford D. Democritus
In which reaction would you expect ΔH to be substantially greater than ΔU (i.e., ΔH> ΔU) ? A) H2O(s) → H2O(t) B) H2(g) + Br2(g) → 2 HBr(g) C) HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l) D) CO2(s) → CO2(g) E) C2H2(g) + H2(g) → C2H4(g)
CH3COOH
How many moles of sulfate ions are contained in 250 grams of aluminum sulfate? There are 0.731 moles of sulfate ions in 250 grams of aluminum sulfate There are 2.19 moles of sulfate ions in 250 grams of aluminum sulfate. There are 1.46 moles of sulfate ions in 250 grams of aluminum sulfate. There are 2.92 moles of sulfate ions in 250 grams of aluminum sulfate.
Find the area of a square with sides of length 12 in.
The limiting reactant can be identified in a chemical reaction because it (A) is always in the greatest amount at the beginning of the reaction (B) is always in the smallest amount at the beginning of the reaction (C) is not completely consumed during the reaction (D) limits the amount of product formed
HO OH OH
5. Quando o vapor passa para o estado líquido. dizemos que ocorreu: (A) Solidificação (B) Fusão (C) Condensação (D) Sublimação
Remember the structure of salicylic acid? It had a - COOH group. Which functional group would this be? Click VIEW IMAGE to see the structure of salicylic acid. a) Carboxylic acid b) Aldehyde c) Amine d) Haloalkane
The pH of a* 0.88 M solution of hydrocyanic acid (HCN) is measured to be 4.63. Calculate the acid dissociation constant Ka of hydrocyanic acid. Be sure your answer has the correct number of significant digits.
Part A Express the group number as an integer. Part B Express the group number as an integer. Part C Express the group number as an integer.
Why does molecular fluorescence often occur at a longer wavelength than the exciting radiation? Select one: Internal conversion: Addition of energy from solvent molecules to the species in the lowest vibrational level of an electronically excited state. Stokes shift: Loss of energy due to non-radiative transitions from an excited vibrational energy level to the lowest vibrational level of an electronically excited state, from which a photon is ther emitted. Addition of energy from an excited vibrational level to the highest vibrational level of an electronically excited state. Loss of energy due to radioactive transitions from an excited vibrational energy level to a lower vibrational level of an electronically excited state, with the emission of fluorescence. CHECK
What quantity of heat (in kJ ) is absorbed in the process of making 0.781 mol of CF4 from the following reaction? C(s)+2 F2(g) → CF4(g) ΔH°=141.3 kJ / mol
If 50.0 g of H2 and 109.0 g of O2 react, how many moles of H2O can be produced in the reaction below? The balanced equation is 2 H2(g) + O2(g) → 2 H2O(g)
Electronic Structure and Chemical Bonding Interpreting the radial probability distribution of an orbital Here is a sketch of the radial probability distribution of three orbitals: Use this sketch to answer the following questions.
Calculate the bond dissociation energy needed to break all the bonds in a mole of carbon dioxide, CO2. Express your answer as an integer and include the appropriate units.
Acids and Bases Predicting the qualitative acid-base properties of salts Consider the following data on some weak acids and weak bases: - acid - name: hydrocyanic acid, formula: HCN, Ka: 4.9 x 10^-10 - name: nitrous acid, formula: HNO2, Ka: 4.5 x 10^-4 - base - name: methylamine, formula: CH3NH2, Kb: 4.4 x 10^-4 - name: hydroxylamine, formula: HONH2, Kb: 1.1 x 10^-8 Use this data to rank the following solutions in order of increasing pH. In other words, select a '1' next to the solution that will have the lowest pH, a '2' next to the solution that will have the next lowest pH, and so on. - 0.1 M CH3NH3Cl: choose one - 0.1 M KCN: choose one - 0.1 M KI: choose one - 0.1 M NaNO2: choose one
The US Department of Energy reported that 47% of homes were heated by natural gas. A random sample of 333 homes in Oregon found that 144 were heated by natural gas. Test the claim that proportion of homes in Oregon that were heated by natural gas is different than what was reported. Use a 5% significance level. Give answer to at least 4 decimal places. a. What are the correct hypotheses? (Select the correct symbols and use decimal values not percentages.) b. Test Statistic = c. p-value = d. Based on the above we choose to e. The correct summary would be: that the proportion of homes in Oregon that were heated by natural gas is different than what the DOE reported value of 47%.
UCSD is one of the first schools to create a department of NanoEngineering. The prefix "nano" refers to very small things and is based on a size definition from chemistry. A nanometer is 1 · 10^-7 meters. Similarly, a nanoliter is 1 · 10^-9 liters. Solve the below problems and write your answer in scientific notation. (a) The width of a human hair is about 80000 nanometers. Find the length in meters. (b) A triangular nanoparticle (often used as a catalyst or for drug delivery) has a base of 4 nanometers and height of 6 nanometers. Find the area in square meters. (c) A spherical virus has a radius of 20 nanometers. Find the approximate volume in cubic meters. Note that the volume, V, of a sphere with radius, r, is V = 4/3 π r^3. Use r ≈ 3 when doing your calculation.
An analytical chemist weighs out 0.115 g of an unknown monoprotic acid into a 250 mL volumetric flask and dilutes to the mark with distilled water. He then titrates this solution with 0.1500 M NaOH solution. When the titration reaches the equivalence point, the chemist finds he has added 7.9 mL of NaOH solution. Calculate the molar mass of the unknown acid. Be sure your answer has the correct number of significant digits.
How do antioxidant minerals stabilize free radicals? donate electrons or hydrogens
Identify the properly written and balanced equation for the reaction between sulfuric acid and magnesium hydroxide. HSO4 + 2 MgOH → 2 MgSO4 + H2 O 2 H2 SO4 + Mg(OH)2 → MgSO4 + 2 H2 O HSO4 + MgOH → MgSO4 + H2 O H2 SO4 + Mg(OH)2 → MgSO4 + 2 H2 O