Chemistry Homework Questions & Answers Archive

The pKa of lactic acid is 3.9. A lactate buffer will be useful from pH values - 3.5 through 4.4 - 3.0 through 4.5 - 2.9 through 4.9 - 3.8 through 4.0

View Assessment CHEM-0109-01 General Chemistry (2024FA) - Online Module-2-Exam (i) This assessment contains questions that allow partial and negativ () 122 minutes remaining Exams Content Page 37 of 49 Question 37 The instrument used for detecting radiation is (A) Barometer (B) Tachimeter (C) Geiger Counter (D) Anemometer (E) none of the above Last saved 11:39:03 PM Questions Filter (49) First

Nucleic acids absorb light strongly in the ultraviolet region of the spectrum because they have double-bond systems. Unsaturated Unconjugated Conjugated Saturated

What volume, in milliliters, should be reported? Enter a number with correct significant figures.

Complete the table below. For example, in the first row decide whether Sc^3+ is a cation or anion. In the second row, write the symbol for the ion that an atom sulfur is mostly likely to form and then decide what type of ion it is. element most likely ion --- --- --- symbol of ion type of ion scandium Sc^3+ cation anion sulfur cation anion iodine cation anion cesium cation anion barium cation anion

Hospital admissions: The following frequency distribution presents the five most frequent reasons for h in U.S. community hospitals in a recent year. Reason Frequency (in thousands) Congestive heart failure 923 Coronary atherosclerosis 1344 Heart attack 706 Infant birth 4233 Pneumonia 1147 (a) Construct a relative frequency distribution. Round the answers to two decimal places. Reason Relative Frequency Congestive heart failure Coronary atherosclerosis Heart attack Infant birth Total

Elements and Symbols in the Periodic Table Part A Arrange the following elements in order of increasing atomic mass. Rank the masses of the elements from lightest to heaviest. To rank items as equivalent, overlap them. View Available Hint(s) Reset Help Mg(Pb K Cl Fe B C

Calculate Kp for the reaction 2 NOCl(g) ⇌ 2 NO(g) + Cl2(g) at 400 °C if KC at 400 °C for this reaction is 2.1 × 10^-2 (R=0.08206 L · atm / K · mol)

Select the correct answer based on the information and question below [CH₄]

What are the angles (a) and (b) in the actual molecule of which this is a Lewis structure?

Examine the biochemical reaction below: CH3CH2OH + NAD+ ↔ CH3CHO + NADH + H+ Which of the following molecules is reduced in the aforesaid reaction? EtOH NAD+ NADH Acetaldehyde

Lab Quiz Review UNIVERSITY - Practice Question - Find the correct information for XeF2: # of electron groups, electron geometry, bond angle, # of bonded atoms, molecular geometry, - A) 5, trigonal bipyramidal, 120 90, 2, linear - B) 3, trigonal planar, 120, 2, bent - C) 4, tetrahedral, 109.5, 2, bent - D) 2, linear, 180, 2, linear

If a reaction is exergonic, what is the free energy change? It equals zero. It is positive. It could be either positive or negative depending on the reaction. It is negative. Submit Request Answer

What is the term used to describe the energy of a system that is available to do work? - Free energy - Enthalpy - Kinetic energy - Entropy

What else is produced during the combustion of propane, C3H8? C3H8 + 5 O2 -> 3 CO2 + 4 H2O C3H8 O2 C3H8O2

Consider the reaction below which has a ΔG=+0.5 kJ/mol: A+B ⇌ C+D 10 M A, 10 M B, 1 M C and 1 M D are added to a container at room temperature. Which of the following statements is TRUE? To reach equilibrium, the reaction will proceed in the forward direction. To reach equilibrium, the reaction will proceed alternating between forward and reverse direction. To reach equilibrium, the reaction will proceed in the reverse direction. To reach equilibrium, the reaction will NOT proceed in either direction.

Identify the reaction type for each generic chemical equation. A+B -> AB: AB -> A+B: Hydrocarbon + O2 -> CO2 + H2O: AB + CD -> AD + CB:

Rather than measure the zone diameters, can you make an accurate treatment determination by comparing the presence and relative size of the zones of inhibition?

The molar mass of calcium hydroide is 74.1 g / mol 38.1 g / mol 114 g / mol 73.1 g / mol 63.55+57.1 g / mol

Draw the Lewis dot structure for NI₃. Determine the electron geometry of NI₃. trigonal planar tetrahedral linear

Choose the answer that best matches the description or term. A. ADH B. aldosterone C. ANP D. NO E. norepinephrine B locally acting; causes vasodilation

Change the coefficient(s) to correctly balance the unbalanced equation. 3 NO2(g) + H2 O(l) → HNO3(aq) + 2 NO(g)

What is the molecular shape of COCl2? linear bent tetrahedral trigonal pyramidal trigonal planar The C-Cl bond in COCl2 is What is the Cl-C-Cl bond angle? 120° 180° <109.5° 109.5° The molecule COCl2 is nonpolar. polar

Part A ICl Spell out the full name of the compound. Part B SF6 Spell out the full name of the compound. Part C I4 O9 Spell out the full name of the compound.

For oxyacids of the same general structure but differing electronegativities of the central atoms, acid strength decreases with increasing electronegativity of the central atom. The strongest acid known is HF because Acid strength in a series of fluorine is the most H-A molecules increases electronegative element. with increasing size of A.

Chemically pure substances will freeze: Over a range of temperatures. At a specific temperature. Chemically pure substances tend not to freeze.

A 24.0 g sample contains 14.6 g Cl and 9.40 g B. What is the percent composition of chlorine in this sample? - Your answer should have three significant figures.

Powdered sugar in a box has a density of 0.52 grams per cubic centimeter and a volume of 250 cubic centimeters. Calculate its mass. Write your answer as a whole number. grams

Question 10 ( 0.25 points) The only polyatomic cation is: NH4+ NO2+ NO3+ OH+ Question 11 ( 0.25 points) When writing formulas that include polyatomic ions, parenthesis are included when: one polyatomic ion is needed in a formula. a polyatomic ion is needed in a formula regardless of the quantity. more than a single polyatomic ion is needed in a formula.

Indicate whether the following reactions are homogeneous or heterogeneous: Ti(s) + 2 Cl2(g) ⇌ TiCl4(l) 2 C2H4(g) + 2 H2O(g) ⇌ 2 C2H6(g) + O2(g) 2 C8H18(l) + 25 O2(g) ⇌ 16 CO2(g) + 18 H2O(l) 4 HCl(aq) + O2(g) ⇌ 2 H2O(l) + 2 Cl2(g) C(s) + 2 H2(g) ⇌ CH4(g) 2 C8H18(l) + 25 O2(g) ⇌ 16 CO2(g) + 18 H2O(g) 2 O3(g) ⇌ 3 O2(g)

The water-gas shift reaction CO(g)+H2O(g) ⇌ CO2(g)+H2(g) is used industrially to produce hydrogen. The reaction enthalpy is ΔH∘=−41 kJ. Part A To increase the equilibrium yield of hydrogen would you use high or low temperature? We would use temperature. For an reaction such as this, temperature increases the value of K and the amount of products at equilibrium.

Write the formula for each of the following: a. sodium carbonate b. nitrogen dioxide c. aluminum nitrate d. copper(I) nitride e. potassium phosphate f. cobalt(III) sulfate

4. Define specific heat.

Question 8 (2 points) Identify the given alkane. a) pentane b) hexane C) octane d) heptane

Substrates

QUESTION 8 Ammonium nitrate fertilizer is sometimes used as an explosive. How many moles of water can be formed from the decomposition of 13.2 moles of ammonium nitrate? a. 26.4 mol 2 NH4NO3 → 2 N2+O2+4 H2O b. 14.0 mol c. 13.2 mol d. 18.0 mol e. 6.60 mol

H H H H H — C — C — C — C — H H H H H

A 20% KCl solution should contain grams of KCl in milliliters of water.

The density of water is 1.00 g/mL at 4°C. How many water molecules are present in 2.86 mL of water at this temperature? Be sure your answer has the correct number of significant digits. Note: Reference the Fundamental constants table for additional information. molecules

Question 14 2 pts While explaining the irradiation of food to a nutrition class, you give your students a list of foods allowed to be irradiated in the United States. Which of the following foods would you expect to find on this list? (mark all that apply) (CO7) Jelly White potatoes Wheat flour Pork

16. Based on the video what happened to the beaker of water when HCL (hydrochloric acid was added)? Please answer in detail 2 pts 17. Based on the video what happened to the beaker of water when NaOH (hydrochloric acid was added)? Please answer in detail 2 pts

Decide whether each pair of elements in the table below will form an ionic compound. element #1 element #2 Forms ionic compound? empirical formula of ionic compound --- --- --- --- bromine lithium yes oxygen iodine yes cesium sulfur yes no fluorine calcium yes no

Classify each of the following molecules as polar or nonpolar.

Practice Exercises Balance the following single replacement reactions. 1. Al+Fe3O4 → Al2O3+Fe 2. Zn+HCl → H2+ZnCl2 3. Fe+CuSO4 → FeSO4+Cu 4. Cu+AgNO3 → Ag+Cu(NO3)2 5. Na 6. Al+H2O Pb(NO3)2 → NaOH+Al(NO3)2+H2 Double Replacement CaCO3+2 HCl → CaCl2+H2CO3 Double Replacement Ca(OH)2+2 H3PO4 → Ca3(PO4)2+H2O

What is the purpose of a hot filtration? prevent viruses during filtration prevent yeast during filtration prevent bacteria during filtration minimize crystal formation during filtration This is the process which the compounds of the mixture are separated by pouring out the liquid so as not to disturb the solids that readily settle at the bottom of the container. Distillation Decantation Chromatography Sublimation

These are too small to be separated by filtration and centrifugation. Colloidal Suspension Class suspension Collodial Suspension None of the mentioned choices What is the advantage of vacuum filtration? None of the mentioned choices Cost effective Increase the rate of filtration Low power consumption

The following reaction occurs in basic solution. Please balance the following reaction and fill in the missing coefficients ClO2^-(aq) + HPO3^2-(aq) -> Cl^-(aq) + PO4^3-(aq) - Do not include the state (phase) information. - Include all coefficients, even those equal to 1. Provide your answer below: OH^- ClO2 HPO3^2- Cl^-+ PO4^3-+ H2O

Drop the coefficients into the boxes to balance the redox equation shown in the figure. While it is conventional to not show coefficients of 1, in this exercise it is okay to do so MnO4, C2O42- + Mn2+ + CO2 + H2O 1 2 4 5 6 8 10 12 16

Part C If 27.0 mL of an AgNO3 solution is needed to precipitate all the Cl- ions in a 800-mg sample of KCl (forming AgCl ), what is the molarity of the AgNO3 solution? Express the molarity in the moles of a solute per liters of a solution to three significant figures. Molarity = M Part D If 46.0 mL of 0.106 M HCl solution is needed to neutralize a solution of KOH, how many grams of KOH must be present in the solution? Express the mass in grams to three significant figures. m = g

Identifying Properties of Subatomic Particles Particle Charge Location Approximate mass (amu) Made of quarks? --------------- Proton +1 Nucleus 1 yes Neutron 0 Nucleus 1 yes Electron -1 Orbitals 0 no Complete the table to summarize the properties of the different subatomic particles by typing in "yes" or "no."

Which gland is thought to play a role in establishing 24-hour circadian rhythms? Pineal gland Thyroid gland Hypothalamus Pituitary gland

A student proposes the following Lewis structure for the nitrate (NO3-) ion. Assign a formal charge to each atom in the student's Lewis structure. atom formal charge central O N right O left O

Question 7 1 pts A proposed mechanism for the reduction of nitrogen as NO by hydrogen is: Step 1 (slow): H2(g) + 2 NO(g) -> N2O(g) + H2O(g) Step 2 (fast): N2O(g) + H2(g) -> N2(g) + H2O(g) If the proposed mechanism is correct, which of the following statements is NOT true? - the activation energy for step 2 probably less than that of step 1 - the reaction rate is second order in NO - N2O is the transition state - the reaction rate is probably the first order in H2 - the energy diagram for this reaction has two maxima

Question 40 1 pts An estrogen compound with the empirical formula C12H17O2 has a molecular mass of 386.6 g / mol. What is the value of n necessary to find the molecular formula? 2 0.2 20 1 none of the above

Determine the empirical formula for a compound that has 95 g C and 5 g H.

An aqueous solution at 25°C has a H3O+ concentration of 7.6 x 10^-8 M. Calculate the OH- concentration. Be sure your answer has the correct number of significant digits.

Based on your answer in Part B, how many neutrons are in this amount of ^13C? Express your answer numerically in neutrons.

A brick has a mass of 4.0 kg and the Earth has a mass of 6.0 x 10^27 g. Use this information to answer the questions below. Be sure your answers have the correct number of significant digits. What is the mass of 1 mole of bricks? Round your answer to 2 significant digits.

Which is the stronger base? CH3CH2CH2COO^- CH3CH2CH2NH2

What is the chemical formula for nitric acid? a. H2NO2 b. HNO3 c. H2NO3 d. HNO4 e. HNO2

Part F chromium(III) sulfate Express your answer in atomic mass units to one decimal place. Formula weight = amu Submit

What is the ion symbol for the phosphide ion? P^3-

Name the compound CuSO4. Copper(I) sulfate Copper(I) sulfite Copper(II) sulfite Copper(II) sulfate Copper(IV) sulfate

Measurement and Matter Naming ionic compounds with common polyatomic ions Fill in the name and empirical formula of each ionic compound that could be formed from the ions in this table: Some ionic compounds cation anion empirical formula name of compound Mg^2+ OH^- Fe^3+ NO2^- K^+ CN^-

What is the volume of a 2.5 g block of metal if its density is 4.75 g / cm^3 ? 0.53 cm^3 1.9 cm^3 2.5 cm^3 4.75 cm^3 11.9 cm^3

What is referred to as a "group" when discussing molecular shapes?

Which quantity is an inexact number? 10 dogs 25 atoms 50 meters 1 dozen eggs 3 rulers

Calcular el área de la región sombreada. A) 152/3 B) 165/4 C) 625/12 D) 128/3

Name: CHEM 111 Quiz 3 1) Given the reaction 2 A(g) -> B(g) + C(g) a) Express the rate of reaction in terms of the change in concentration in terms of the change in concentration of each of the reactants and products. b) When [C] is increasing at 2.0 mol / L s, how fast is [A] decreasing?

Radioisotopes of an element (Select all that apply) emit energy can be used in diagnostic procedures such as indium scans

Which statement correctly describes radioactive isotopes? Multiple Choice They are unstable, but can become stable by bonding with other isotopes. They are stable and will decompose, releasing energy. They are stable and can participate in chemical bonding They are unstable and will decompose, releasing energy.

Decide whether the Lewis structure proposed for each molecule is reasonable or not. molecule proposed Lewis structure Is this a reasonable structure? If not, why not? BF3 : F: : F-B-F: Yes, it's a reasonable structure. No, the total number of valence electrons is wrong. The correct number is: No, some atoms have the wrong number of electrons around them. The symbols of the problem atoms are: NH2+ [H-N=H]+ Yes, it's a reasonable structure. No, the total number of valence electrons is wrong. The correct number is: No, some atoms have the wrong number of electrons around them. The symbols of the problem atoms are: BH2+ [H-B-H]+ Yes, it's a reasonable structure. No, the total number of valence electrons is wrong. The correct number is: No, some atoms have the wrong number of electrons around them. The symbols of the problem atoms are: * If two or more atoms have the wrong number of valence electrons around them, just enter the chemical symbol for the atom as many times as necessary. For example, if two oxygen atoms have the wrong number of electrons around them, enter the symbol O twice.

Enter your answer rounded to 1 decimal place. Do not use a negative sign. What is the opportunity cost of one more candy bar? bag(s) of peanuts Of one more bag of peanuts? candy bar(s) Do these opportunity costs rise, fall, or remain constant as additional units are purchased? (Click to select) Does the budget line tell you which of the available combinations of candy bars and bags of peanuts to buy? (Click to select) Suppose that you had won 30 on your ticket, not 15. Is the slope of a new budget line flatter, steeper, or the same as in the diagram above? (Click to select)

The breakdown of a certain pollutant X in sunlight is known to follow first-order kinetics. An atmospheric scientist studying the process fills a 35.0 L reaction flask with a sample of urban air and finds that the partial pressure of X in the flask decreases from 0.994 atm to 0.385 atm over 60 minutes. Calculate the initial rate of decomposition of X, that is, the rate at which X was disappearing at the start of the experiment. Round your answer to 2 significant digits. atm/s

SiH4 and NH3 both have an identical electron domain geometry. However, SiH4 has a tetrahedral molecular geometry while NH3 has a trigonal pyramidal molecular geometry. Draw a Lewis structure of each molecule and indicate their electron domain geometry.

In each of the molecules drawn below, one chemical bond is circled. Decide whether this bond is likely to be polar or not. If the bond is polar, write down the chemical symbol for the atom which will have more negative charge.

Name each covalent compound. Part 1 of 3 SiBr4: Part 2 of 3 SF2: Part 3 of 3 N2O:

Reactivity with acid Aluminum: Select an answer Magnesium: Select an answer Copper: Select an answer

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 methyl acetate, acetone, tetrahydrofuran, carbon tetrachloride, and dimethyl sulfoxide. The chemist plans to try to identify the unknown liquid by measuring the density and comparing to known densities. First, from her collection of Material Safety Data Sheets (MSDS), the chemist finds the following information: liquid density methyl acetate 0.93 g/mL acetone 0.79 g/mL tetrahydrofuran 0.89 g/mL carbon tetrachloride 1.6 g/mL dimethyl sulfoxide 1.1 g/mL Next, the chemist measures the volume of the unknown liquid as 1489 cm^3 and the mass of the unknown liquid as 1.05 kg. Calculate the density of the liquid. Be sure your answer has the correct number of significant digits. g / mL Given the data above, is it possible to identify the liquid? yes no If it is possible to identify the liquid, do so. methyl acetate acetone tetrahydrofuran

Electronic Structure and Chemical Bonding Predicting the single-bonded molecular compounds formed by two... For each row in the table below, decide whether the pair of elements will form a molecular compound, check the box and enter the chemical formula and name of the compound. (When multiple compounds are possible, use the compound with the fewest total number of atoms.) You may assume all chemical bonds are single bonds, not double or triple bonds. element #1 element #2 element pair will form a molecular compound chemical formula name --------------- barium chlorine ☐ ☐ ☐ hydrogen chlorine ☐ ☐ ☐ nitrogen hydrogen ☐ ☐ ☐

Part A How many moles of methane are produced when 59.6 moles of carbon dioxide gas react with excess hydrogen gas? Express your answer with the appropriate units. View Available Hint(s) Value Units Submit

A sample of sodium reacts completely with 0.142 kg of chlorine, forming 234 g of sodium chloride. What mass of sodium reacted? Express your answer to three significant figures and include the appropriate units.

What is the highest temperature allowed for cold-holding turna salace? a. 41 degrees F (5 degrees C) b. 50 degrees F (10 degrees C) c. 59 degrees F (15 degrees C) d. 68 degrees F (20 degrees C)

Classify the compounds as acids, bases, or salts. Acid Base Salt Answer Bank LiOH NH4Cl H2C2O4 Ca(OH)2 KNO3 HI BaF2 HClO4

Which of the following statements about enzyme function is correct? None of the listed responses is correct. Enzymes can greatly speed up reactions, but they cannot change the net energy output because they cannot change the activation energy. Enzymes can change the equilibrium point of reactions, but they cannot speed up reactions because they cannot change the net energy output. Enzymes can lower the activation energy of reactions, but they cannot change the equilibrium point because they cannot change the net energy output. Enzymes can greatly speed up reactions, but they cannot change the activation energy because they cannot change the net energy output.

What is the approximate pH of a 0.10 M solution of a weak acid that has a Ka of 5 times 10^-5 M ?

Problem 4.77 Review Constants Periodic Table Pure acetic acid, known as glacial acetic acid, is a liquid with a density of 1.049 g / mL at 25°C. Part A Calculate the molarity of a solution of acetic acid made by dissolving 28.00 mL of glacial acetic acid at 25°C in enough water to make 290.0 mL of solution. Express your answer using four significant figures.

Review the item in each row in the table below and identify whether it is an element, compound, or mixture. If it is a mixture, then also specify whether heterogeneous or homogeneous.

What is wrong with writing the formula for tin(II) bicarbonate as Sn2(HCO3)2 ?

When you put things in order, it means the entropy is being . a. increased b. decreased

The following table shows the distribution of murders by type of weapon for murder cases in a particular country over the past 12 years. Complete parts (a) through (e). Weapon Probability Handgun 0.473 Rifle 0.022 Shotgun 0.032 Unknown firearm 0.148 Knives 0.134 Hands, fists, etc. 0.053 Other 0.138 (d) What is the probability that a randomly selected murder resulted from a weapon other than a gun? P (weapon other than a gun) = 0.325 (Type a decimal rounded to three decimal places as needed.) Interpret this probability. Select the correct choice below and fill in the answer box to complete your choice. A. If 1000 murders were randomly selected, exactly of them would have resulted from a weapon other than a gun. B. If 1000 murders were randomly selected, we would expect about of them to be have resulted from a weapon other than a gun.

Polynomial and Rational Functions Finding the intercepts, asymptotes, domain, and range from the graph of ... The graph of a rational function f is shown below. Assume that all asymptotes and intercepts are shown and that the graph has no "hole Use the graph to complete the following. (a) Write the equations for all vertical and horizontal asymptotes. Enter the equations using the "and" button as necessary. Select "None" as necessary. Vertical asymptote(s): Horizontal asymptote(s): (b) Find all x-intercepts and y-intercepts. Check that apply. x-intercept(s): -4 -1 2 None y-intercept(s): -1 0 1 None (c) Find the domain and range of f. Write each answer as an interval or union of intervals. Domain: Range:

According to the Fluid Mosaic Model, the component/s of plasma membranes is/are... A phospholipid bilayer Integral and peripheral proteins Glycolipids Glycoproteins All of the above

Draw an alkane containing one tertiary carbon atom, one secondary carbon atom, and three primary carbon atoms. Show all hydrogen atoms.

Calculate the range, population variance, and population standard deviation for the following data set. If necessary, round to one more decimal place than the largest number of decimal places given in the data. 13,13,13,13,13,13,13,13,13,13 Range: Population Variance: Population Standard Deviation:

Decide whether each chemical reaction in the table below is an oxidation-reduction ("redox") reaction. If the reaction is a redox reaction, write down the formula of the reducing agent and the formula of the oxidizing agent. 7 O2(g) + 2 CH3CH3(g) → 4 CO2(g) + 6 H2O(g) redox reaction? yes no reducing agent: oxidizing agent: HNO3(aq) + H2O(l) → H3O+(aq) + NO3-(aq) redox reaction? yes no reducing agent: oxidizing agent: CuSO4(aq) + Zn(s) → ZnSO4(aq) + Cu(s) redox reaction? yes no reducing agent: oxidizing agent:

Element X has an average atomic mass of 44.68574 amu and has two isotopes. One isotope of element X has an atomic mass of 45.57456 amu and a percent abundance was measured to be 14.29%. What is the atomic mass of the other isotope? Your answer MUST have the correct number of significant figures.

This question has multiple parts. Work all the parts to get the most points. The reaction 2 NO(g)+2 H2(g) rightarrow N2(g)+2 H2O(g) was studied at 904^circC, and the data in the table were collected. Trial Reaction Concentration (mol/L) Rate of Appearance of N (mol/L-s) --------- [NO] [H2] 1 0.420 0.122 0.136 2 0.210 0.122 0.0339 3 0.210 0.244 0.0678 4 0.105 0.488 0.0339 Which two reaction trials can be used to determine the order of the reaction in [NO]? and

¿Cuál de las siguientes afirmaciones sobre la cinética enzimática de Michaelis-Menten es correcta? (A) Km es la concentración de sustrato requerida para convertir la de la concentración de sustrato a producto. (B) La Km representa la constante de velocidad de la etapa limitante de la velocidad de un proceso catalizado por una enzima. (C) La Km es expresada en términos de una velocidad de reacción (mol/seg.) (D) Una enzima con mayor km tiene menor afinidad por su sustrato que una de menor km.

app.aktiv.com Question 9 of 15 What is the atomic number for an element whose mass number is 78 , which contains 38 neutrons per atom?

the lower the melting point.

One of the inherently satisfying features of chemistry is that chemical materials form and interact in a rational and predictable manner. For example, one can predict a great deal about a particular material's properties by systematically determining the percentage composition of the elements in that compound. This gives us the relative proportions of the elements in the sample. For a molecular made up of elements A, B, and C, the empirical formula AxByCz means that there are two atoms of C for each atom of A and each atom of B. This may not be the actual chemical formula, which might instead be A2B2C4, but it is the "reduced" version of that formula, called the empirical formula. The actual formula is some multiple of the empirical formula. To know the actual formula we need to know both the empirical formula and the molecular mass of the compound. This provides us with the multiplier value in whole units that must be applied to the empirical formula to get the actual formula. A compound is 40.0% C, 6.70% H, and 53.3% O by mass. Assume that we have a 100-g sample of this compound. Part A What are the subscripts in the empirical formula of this compound? Enter the subscripts for C, H, and O, respectively, separated by commas (e.g., 5,6,7). 1,2,1 The empirical formula of the compound is CH2O. Part B The molecular formula mass of this compound is 120 amu. What are the subscripts in the actual molecular formula? Enter the subscripts for C, H, and O, respectively, separated by commas (e.g., 5,6,7).

Does any element with Z ≤ 92 match the description? If you checked yes, give the symbol of an element with Z ≤ 92 that matches. An element in Period 4 and Group 8A. A metalloid in Group 5A. An alkaline earth metal with a lower atomic number than lithium. A main-group element in Period 3.

C. The reaction of NO2(g) and CO(g) is thought to occur in two steps: Step 1 slow NO2(g)+NO2(g) → NO(g)+NO3(g) Step 2 Fast NO3(g)+CO(g)+NO2(g)+CO2(g) What is the molecularity of Step 2? bimolecular termolecular unimolecular (d) The reaction of NO2(g) and CO(g) is thought to occur in two steps: Step 1 Slow NO2(g)+NO2(g) → NO(g)+NO3(g) Step 2 Fast NO3(g)+CO(g) → NO2(g)+CO2(g) For this mechanism to be consistent with kinetic data, what must be the experimental rate equation? rate =k[NO2] rate =k[NO2]^2 rate =k[NO2][CO]

Considered late if submitted after 11 pm on the due date. Question 6 5 pts is the force of gravity that is exerted on an object. While is the quantity of matter in a given sample of a substance.

Calculate the mass of sodium chlorate that is used to form 7.5 g of oxygen given the balanced chemical equation. (The molar mass of O2 is 32.00 g / mol; NaClO3 is 106.44 g / mol.) 2 NaClO3(s) -> 2 NaCl(s) + 3 O2(g)

Question 3 (2.38 points) Match the lettered functional group name to the picture given. A is C is B is E is D is 1. Hydroxyl 2. Carboxyl 3. Amino 4. Sulfhydryl 5. Phosphate

Complete the following table: two polyatomic anions name chemical formula 10^- chlorate anion

Specify the formal charges (both sign and magnitude) on the atoms labeled a-c.

Identify the following reaction C- hydrogenation acid hydrolysis base hydrolysis esterification

Write the name for 54^129 X. Write the number of protons and neutrons for 54^129 X. Express your answers as integers separated by a comma. Nprotons, Nneutrons= Write the symbol for 53^129 X. Express your answer as a chemical symbol.

Nitric acid and nitrogen monoxide react to form nitrogen dioxide and water, like this: 2 HNO3(aq) + NO(g) → 3 NO2(g) + H2O(l) At a certain temperature, a chemist finds that a 2.7 L reaction vessel containing a mixture of nitric acid, nitrogen monoxide, nitrogen dioxide, and water at equilibrium has the following composition: compound amount HNO3 23.5 g NO 10.2 g NO2 6.8 g H2O 238.1 g Calculate the value of the equilibrium constant Kc for this reaction. Round your answer to 2 significant digits. Kc=

Na2CO3(aq) + CaCl2(aq) → 2 NaCl(aq) + CaCO3(s) Calculate the volume (in mL) of 0.100 M Na2CO3 needed to produce 1.00 g of CaCO3(s) There is an excess of CaCl2. Molar mass of calcium carbonate = 100.09 g / mol Volume of sodium carbonate = mL

Consider the first-order decomposition of H2O2 with the rate constant of 1.8 x 10^-5 s^-1 at 20°C. What is the half-life (in hours) of the reaction at 20°C? Express your answer using two significant figures. What is the molarity of H2O2 after four half-lives if the initial concentration of H2O2 is 0.36 M? Express your answer using two significant figures.

Which equation correctly represents the dissociation of a carboxylic acid in water? CH3COOH ⇌ CH3COO^- + H^+ CH3COOH + H2O ⇌ CH3COO^- + H3O^+ CH3COOH + H2O ⇌ CH3CHCOOH2^+ + OH^- CH3COOH + H3O^+ ⇌ CH3COOH2^+ + H2O CH3COOH + 2 H2O ⇌ CH3COO^2- + 2 H3O^+

Assume that the change in concentration of COCl2 is small enough to be neglected in the following problem. (a) Calculate the equilibrium concentration of all species in an equilibrium mixture that results from the decomposition of COCl2 with an initial concentration of 0.3166 M. COCl2(g) ⇌ CO(g) + Cl2(g) Kc=2.2 × 10^-10 (b) Confirm that the change is small enough to be neglected.

Calculate the freezing point and boiling point of a solution containing 8.00 g of ethylene glycol (C2H6O2) in 928 mL of ethanol. Ethanol has a density of 0.789 g / cm^3. Part A Calculate the freezing point of the solution. (Use Kf=1.99°C / m and normal freezing point =-114.1°C.) Express the answer using four significant figures. TY= C

QUESTION 1 The chemical properties of an element depend strongly upon what? - the mass number of the element - the number of neutrons in its nucleus - the atomic number of the element - the number of protons in its nucleus - the arrangement of its electrons

Part B = Enzyme function and pH Enzymes function best when they are in specific environments. Temperature and pH are two environmental conditions that can have significant impacts on enzyme function. For now, you will focus on proteases, enzymes that break down proteins into their component annino acids. Pepsin is a protease that is found primarily in the stomach of mammals where it helps digest proteins present in food 1. Reset the simulation to its defaul settings. Note the initial amount of proteins in the solution and the color of the tube with the biuret solution indicator. 2. In the Enrymes section of the simulation, select "Add Pepsin." 3. The delault pH is 7. Run the simulation at pH 7 and make a note of the amount of amino acids produced after 20 minutes and the color of the tost tube. 4. Next, run the simulation at pH 5 and note the concentration of amino acids atter 20 minutes. Also note the color of the lest tube 5. Run the simulation at pH 2 and at pH 12 . Pay aftention to how the concentration of amino acids produced varies with pH . At which pH did pepsin function the best? in other words, at which pH were the most amino acids produced after 20 minutes? Pepsin functioned best at pH 2 . Pepsin functioned best at pH 5. Pepsin functioned best at pH 7 . Pepsin functioned best at pH 12 . Submit Bequest Ansintr

Balance the chemical equation below using the smallest possible whole number stoichiometric coefficients. H₂(g) + P₄(s) → PH₃(g)

The reaction A=B was run with an initial concentration of 0.26 M . Determine the equilibrium concentration (in M ) of B given that the rate constant is 7,018 . REPORT YOUR ANSWER TO 2 DECIMAL PLACES. DO NOT INCLUDE UNITS.

Below are several constitutional isomers with the molecular formula C6H14. Which of these isomers will have the largest heat of combustion?

CO3^2-+H2CO3

HCl + CaCO3 → CaCl2 + H2O + CO2

Complete the following table. Round each of your answers to 3 significant digits. food energy content when eaten ------------ cal kcal kJ three ounces of cooked sirloin steak 2.40 × 10^5 240. 100. an ear of cooked corn 8.5 × 10^4 85.0 an ounce of breakfast corn flakes 460.

The name of the binary compound N2O3 is A. nitrogen oxide B. dinitrogen trioxide C. nitrous oxide D. nitrogen (IV) oxide

Factor the following expression. 24 u^3 w^9+18 u w^3 y^6

To study the effect of temperature on yield in a chemical process, five batches were produced at each of three temperature levels. The results follow. Temperature 50°C 60°C 70°C 34 29 22 25 30 29 36 34 28 39 22 29 31 30 32 Construct an analysis of variance table. (Round your values for MSE and F to two decimal places, and your p-value to four decimal places.) Source of Variation Sum of Squares Degrees of Freedom Mean Square F

Chapter 6 - Homework - Attempt 2 Exercise 6.21 MISSED THIS? Watch KCV: The Mole Concept, IWE: Converting between Moles and Number of Atoms: Read Section 6.3. You on the Review link to access the section in your eText. Complete the table: Element Moles Number of Atoms Ne 0.468 Ar - 3.76 × 10^24 Xe 1.60 - He - 1.16 × 10^20

Write the chemical formula for this molecule:

Open Response Questions- Kf(H2O)=1.86°C/m, Kb(H2O)=0.52°C/m, 760 mm Hg=1.0 atm 13) Sea water is primarily composed of 42.3 g of NaCl/kg water. Calculate the freezing point of the oceans.

The equilibrium constant, K₀⁺ for the following reaction is 9.52 x 10⁻² at 350 K: CH₄(g) + CCl₄(g) ⇌ 2 CH₂Cl₂(g) [CH₄]=□ M [CCl₄]=□ M [CH₂Cl₂]=□ M

How many d electrons are in the valence shell of the Cd2+ cation? How many unpaired electron spins? Number of d electrons: Number of unpaired spins:

Solid calcium oxide and carbon dioxide gas are formed by the decomposition of solid calcium carbonate (CaCO3). Write a balanced chemical equation for this reaction.

Quiz: Pre-lab Quiz 5 Week 6 Purpose Submis: If the nD of a fraction is measured to be 1.4653 at 25 deg C, the corrected nD at 20 deg C is 1.4631 1.5732 1.4653 1.4676 One of the fraction's corrected nD at 20 deg C is 1.4563 on the Reichert refractometer, the % toluene of this fraction is

Circle the atom in each group that has the smallest atomic radius. i) Al, N, P, or B iii) Mg, K, Na, Be ii) O, Cl, F, or He iv) C, Cs, Mg, or Si

Quiz: Pre-lab Quiz 5 Week 6 Purpose Submis: ASSIGNMENT Question 1 Match the BP and refractive index to their respective compounds Cyclohexane boils at [Select] , its refractive index is [Select] Toluene boils at [Select] refractive index is [Select] Question 2 The difference between a simple and fractional distillation is that simple distillation is done at much higher temperature fractional distillation has an additional column to separate vapors

Draw skeletal structures corresponding to each of the following IUPAC names: a. cis-1,2-diethylcycloheptane b. 6-isobutyldodecane c. 2-ethyl-1,1-dimethylcyclopropane d. 2,3,3,4-tetramethylpentane

Write a net ionic equation when ferric chloride and sodium hydroxide mix together.

HCl and LiOH react in a neutralization reaction. What two products would I expect from this reaction? Select all that apply. H2O OH LiCl LiH LiOCl

Suppose the following chemical reaction can take place in this mixture: 2 S(s) + 3 O2(g) → 2 SO3(g) Of which reactant are there the most initial moles? Enter its chemical formula: Of which reactant are there the least initial moles? Enter its chemical formula: Which reactant is the limiting reactant? Enter its chemical formula:

A certain element consists of two stable isotopes. The first has a mass of 78.9 amu and a percent natural abundance of 50.5%. The second has a mass of 80.9 amu and a percent natural abundance of 49.5%. What is the atomic weight of the element? amu

Under certain conditions the rate of this reaction is zero order in dinitrogen monoxide with a rate constant of 0.0059 M · s^-1: 2 N2O(g) → 2 N2(g) + O2(g) Suppose a 3.0 L flask is charged under these conditions with 400 mmol of dinitrogen monoxide. After how much time is there only 200 mmol left? You may assume no other reaction is important. Be sure your answer has a unit symbol, if necessary, and round it to the correct number of significant digits.

Determine the limiting reactant and calculate the number of grams of nitrogen dioxide, NO2, that can be formed when 105 g of nitrogen, N2, reacts with 98.5 g of oxygen, O2. N2(g) + 2 O2(g) → 2 NO2(g)

Which of the following is not an example of a reaction requiring activation energy? - boiling water - photosynthesis - starting a car's engine - lighting a campfire In the equation 2 H2 + O2 → 2 H2O, what is the total number of hydrogen atoms on the reactant side? What is the purpose of the flame from a match in lighting a campfire?

Which layer of Earth is best characterized as a layer of soft, hot rock? (1 point) outer core crust inner core mantle

A mixture of gaseous reactants is put into a cylinder, where a chemical reaction turns them into gaseous products. The cylinder has a piston that moves in or out, as necessary, to keep a constant pressure on the mixture of 1 atm. The cylinder is also submerged in a large insulated water bath. From previous experiments, this chemical reaction is known to release 190 kJ of energy. The position of the piston is monitored, and it is determined from this data that the system does 153 kJ of work on the piston during the reaction. Is the reaction exothermic or endothermic? - exothermic - endothermic Does the temperature of the water bath go up or down? - up - down - neither Does the piston move in or out? - in - out - neither Does heat flow into or out of the gas mixture? - in - out - neither How much heat flows? Round your answer to 2 significant digits. - [ ] kJ

Draw arrows indicating the direction of the water movement for each of the thistle tube setups. Molasses in beaker Water in thistle tube Water in beaker Molasses in thistle tube

A variety of hexene derivatives are shown below. List them in order of increasing stability: (1pt) A B C E Ranking:

A chemist prepares a solution of barium chlorate (Ba(ClO3)2) by measuring out 58.2 μmol of barium chlorate into a 400. mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in mol/L of the chemist's barium chlorate solution. Round your answer to 3 significant digits.

Table salt can be separated into sodium and chlorine. Sodium is explo Chlorine is a gas that can kill people. What can be concluded from the statements above? A A harmful compound can become harmless when its elements are separated. B A harmless compound can become harmful when its elements are separated. C Breaking a compound into its separate elements has no noticeable ef D Breaking a compound into its separate elements can create carbon d

Question 4 pH + pOH always equals log(Kw) 14.0 1.00 × 10^-14 pKw

Select the best answer for the question. 19. The production of sleeper cars and dining cars by the Pullman Car Company had a positive impact on the industry. A. finance B. oil C. railroad D. steel

Al(NO3)3 (aq) + NaOH (aq) ----> Al(OH)3 + 3 NaNO3

Aggregate expenditure, or the total amount of spending in the economy, equals A. household spending on durable goods plus business investment spending. B. household spending on durable goods plus household spending on nondurable goods. C. consumption spending plus planned investment spending plus government purchases plus net exports. D. total spending by households plus total spending by businesses.

You decide to record the hair colors of people leaving a lecture at your school. What is the probability that the next person who leaves the lecture will have gray hair? Express your answer as a simplified fraction or a decimal rounded to four decimal places.

Determining the rate-law expression for the reaction below at the temperature at which the tabulated initial rate data were obtained: rate = A + 2B + 3C → Products Experiment Initial [A] Initial [B] Initial [C] Initial Rate 1 0.10 M 0.30 M 0.30 M 0.040 M/min 2 0.20 M 0.30 M 0.30 M 0.080 M/min 3 0.20 M 0.20 M 0.30 M 0.053 M/min 4 0.20 M 0.20 M 0.40 M 0.11 M/min

Calculate the volume occupied by 637 g of SO2 (MM 64.07) at 6.08 × 10^4 mmHg and -23°C.

If 8.32 g of methane reacts How much O2 is used? How much CO2 H2O form?

3. If you found that you need 0.2943 mols of copper, how many grams of copper do you need? (Use the molar mass of copper from above!)

1 mole Na3N 132.1 g Ca(NO2)2 1 mole Ca(NO2)2 157.9 g 1 mole Na3N Ca(NO2)2 P2O6

Convert each of the following measurements or final calculations into grams. 45925 mg

Question 8 (2 points) taken. is defined as being able to obtain the true value with the measurements Accuracy, Precision Trueness, Grouping Precision, Accuracy Righteousness, Calianation

Question 8 (10 points) Check all the substances below that are ionic compounds. PCl3 CaCl2 HCl Na3P TiO2 Srl2

Question 7 (10 points) Check all of the elements below that are metals. hydrogen lithium cesium chromium neon calcium

3. Draw structural or line angle formulas of 2 compounds that illustrate cis-trans isomers in alkenes.

What is the dependent variable of this experiment? The protein concentration (mg / mL) The number of solutions The wavelength of the light used to measure absorbance The A280

Calculate the amount of heat needed to melt 176 g of ice (H2O) and bring it to a temperature of 90.4°C. Be sure your answer has a unit symbol and the correct number of significant digits.

Number of moles H5O / 1 moleNGSSO4 = 0.083 / 0.012 =

What could be a consequence of improper labeling of the sample before dehydration? slower cooling rate Accidental ignition Mixing up samples leading to incorrect data recording Nothing really

Electronic Structure and Chemical Bonding Counting electron pairs in a Lewis structure with double or triple bonds 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:

10. Starch is broken down into glucose by the process of 11. An atom with 2 electrons in its outermost shell will most likely form a/an 12. A chemical which absorbs H+ ions will 16. If an atom gains an electron, it will have a 17. A base has a pH this type of bond (14)

An atomic cation with a charge of +2 has the following electron configuration: [Kr] 5s^2 4d^10 5p^1 What is the chemical symbol for the ion? How many electrons does the ion have? How many 5p electrons are in the ion?

Average 27.92°C 2.43 55.07 NTU

What is the abbreviated electron configuration for nickel (atomic number 28)? (A) (B) [Ar]asisdo (C) [Ar] 3d^8 (D) [Kr] 4523 d 8 (E) [Ar] 4524 p^4

Write the formula for the chromium(II) ion.

Question 6 Table sugar is - glucose, a disaccharide - sucrose, a monosaccharide - sucrose, a disaccharide - glucose, a monosaccharide

What does the saying "the dose makes the poison" mean? What matters is the amount of a toxic substance present; whether or not we are exposed to the toxin is not relevant. Any amount of a dangerous substance is unacceptable and counting the numbers of compounds detected is a reliable way to establish danger. Most substances are toxic at some level of exposure depending on the substance and the nature of the exposure. All substances have equivalent potential for harm, so exposure to any of them is risky.

1 1.1.4 Quiz: Scientific Investigations Question 6 of 10 Which statement describes a controlled experiment? A. It includes only an experimental group. B. It includes only a control group. C. It includes more than one control group. D. It includes a control group and an experimental group. SUBMIT PREVIOUS

Which of the following two amides will react more readily with a nucleophile? Why? Multiple Choice 1, because it is less hindered II, because it is less hindered 1, because it is more strained II, because it is more strained

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