Chemistry Homework Questions & Answers Archive

Pregunta 2 (10 puntos) El diagnostico de intoxicación con leche de magnesia es clinico y se correlaciona con la concentración de magnesio digerida. La leche de Magnesia es una suspensión de Hidróxido de Magnesio, Mg(OH)2 El hidrowido de magnesio presenta el siguiente equilibrio de solubilidad a 25°C Mg(OH)2(s) = Mg2+(ac) + 2 OH-(ac) Kpg=1.8 × 10^-13 i. (4 puntos) Calcule la solubilidad molar del Mg(OH)2 y el pH de esta disolución. Mg(OH)2(s) ⇌ Mg2+(ac) + 2 OH-(ac) Inicio Cambio Equilibrio ii. (2 puntos). Calcule la [Mg2+] en una disolución de pH=9,60. ¿La solubilidad aumenta o disminuye? iii. (4 puntos) ¿Como variará la solubilidad del hidróxido de magnesio tras la adición de NaOH 0,01 M ? Mg(OH)2(s) ⇌ Mg2+(ac) + 2 OH-(ac) Inicio Cambio Equilibrio

Had we compared a series of metal chlorides (NaCl, CaCl2, AlCl3), we would have seen a difference in conductivity values, even though their concentrations are the same ( 0.05 M ): AlCl3 should have the highest conductivity, and NaCl the lowest. To explain, complete the dissociation equations by filling in the missing charges and coefficients. For example: NaCl(aq) → Na+1+Cl-1 would be completed as: NaCl(aq) → 1 Na+1 and 1 Cl-1 CaCl2(aq) → v Ca+v and v Cl-v AlCl3(aq) → v Al+v and v Cl-v

A solution is prepared at 25°C that is initially 0.68 M in diethylamine ((C2H5)2NH), a weak base with Kb=1.3 x 10^-3, and 1.5 M in diethylammonium bromide ((C2H5)2NH2Br). Calculate the pH of the solution. Round your answer to 2 decimal places. pH=

How many grams of Na solid are required to completely react with 19.2 L of Cl2 gas at STP according to the following chemical reaction? Remember 1 mol of an ideal gas has a volume of 22.4 L at STP. 2 Na(s) + Cl2(g) -> 2 NaCl(s)

PREPARING TO READ A The words in blue below are used in the reading passage on pages 25-26. Match the correct form of each word to its definition. Electricity has many uses - we cook with it, and heat and light our homes with it. It also powers our cell phones. Many people consider Thomas Edison - the inventor of the phonograph - to be one of the greatest creative thinkers of all time. Edison was partially deaf. He struggled to find a steady job before eventually becoming a famous inventor. Some inventions are very expensive, so not everyone can afford them. The French chemist Louis Pasteur is famous for his research on the causes and prevention of diseases. 1. (v) to supply the energy needed for something to work 2. (adv) in the end, especially after a lot of problems 3. (n) a form of energy that can be used for heating and lighting 4. (n) the act of making sure that something does not happen 5. (v) to have enough money to pay for something 6. (v) to try very hard to do something that is difficult 7. (adj) able to invent things and have original ideas

A germicide with a(n) square spectrum is most desirable.

Click on the main elimination product of the reaction

What is the name of the compound CCl4? - carbon tetrachloride - carbon trichloride - monocalcium tetrachloride - calcium pentachloride

Which state of matter is NOT conductive for an ionic compound?

Part A How many covalent bonds does carbon form if each of its unpaired electrons participates in one bond? Express your answer numerically as an integer. View Available Hint(s) Submit Part B How many covalent bonds does oxygen form if each of its unpaired electrons participate in one bond? Express your answer numerically as an integer. View Available Hint(s) Submit Part C How many covalent bonds does nitrogen form if each of its unpaired electrons participate in one bond? Express the answer numerically as an integer. View Available Hint(s) Submit

A certain car model was expected to get 532 miles (highway) on 22 gallons of gas. What was the mean number of miles per gallon (mpg)? The mean number of miles per gallon (mpg) is (Round to the nearest tenth as needed.)

Which element cannot be a central element in a compound? sulfur carbon hydrogen oxygen

Researchers found 400 current smokers to volunteer for a study in which each was randomly assigned to one of three treatment groups. Group 1 received an electronic cigarette (e-cig) in which each cartridge contained 7.2 mg of nicotine, Group 2 received an e-cig that contained 5.4 mg of nicotine, and Group 3 received an e-cig that contained no nicotine. The subjects did not know which group they were assigned. During the course of the intervention, subjects dropped out of the study. At the end of the study 68 subjects remained in Group 1, 62 in Group 2, and 57 in Group 3. Results as to whether the subject quit smoking entirely are available below. Complete parts (a) through (g). Study Results A. H0: P1=P2=P3 H1: At least one of the proportions is different from the others. B. H0: Quitting and group are independent. H1: Quitting and group are dependent. C. H0: O1=E1 and O2=E2 and O3=E3 H1: O1 ≠ E1 or O2 ≠ E2 or O3 ≠ E3 D. H0: P1=f2=p3 H1: p1 ≠ p2 ≠ p3

Calculate the percent ionic character for the sodium chloride, NaCl, molecule. The measured dipole moment, μ for sodium chloride is 9.00 D and the Na-Cl bond length is 236 pm, 1 D=3.34 x 10^-20 Cm.

Balance the following chemical equation (if necessary): Al(s) + Pb(NO3)2(aq) → Pb(s) + Al(NO3)3(aq)

Draw the Lewis structure for HSO4^- (where the H is bonded to an O atom) and answer the following questions: a) How many resonance structures are in the Lewis structure for HSO4^-?: 2 b) How many bonding electrons are in the Lewis structure for HSO4^-? 14 c) How many non-bonding electrons are in the Lewis structure for HSO4? 18 d) What is the bond order between S and the terminal O atoms? 1.5

How many valence electrons does Fluorine (F) have? 7 5 8 6

Calculate the pH of each solution at 2 J°C. 1.0 x 10^-3 M HCl pH= 3.0000 0.1 M HNO3 pH= 1.0000 1.0 x 10^-3 M NaOH pH= 11.0000 0.01 M KOH pH=

Express the reverse equilibrium constant for the following reaction. 5CH3(g) + 5/2 Cl2(g) <-> 5 CH3Cl(g) K = [CH3Cl]^5 / [CH3]^5 [Cl2]^(5/2)

Acidosis is a condition in which the pH of the blood falls below the healthy range, and alkalosis is a condition in which the pH of the blood rises above the healthy range. Apply your knowledge of the acid-base balance within the body to predict which body system(s) would be malfunctioning to result in either acidosis or alkalosis?

Choose the correct equilibrium constant expression for the following reaction: I2(aq) + I^-(aq) <=> I3^-(aq) - [I3^-] / [I^-]^2[I2] - [I^-]^2[I2] - 1 / [I3^-] - [I^-]^2[I2] / [I3^-]

What term is used to refer to the accuracy, validity, and consistency of data used and stored over time?

Fe^2+(aq) LiNO3(s) Fe^3+(aq) Li+(aq) Fe(OH)2(s) Fe(NO3)2(aq) NO3^-(aq) OH^-(aq) LiOH(aq) Fe(OH)3(s)

One of the following pictures (Figure 1) represents NaCl and one represents MgO. Part A Which is which? (a) is NaCl and (b) is MgO (b) is NaCl and (a) is MgO Part B Which has the larger lattice energy? NaCl MgO

Question 1.12: The accompanying summary data on CeO2 particle sizes (nm) under certain experimental conditions was read from a graph in the article "Nanoceria - Energetics of Surfaces, Interfaces and Water Adsorption" (J. of the Amer. Ceramic Soc., 2011:3992-3999): 3.0-<3.5 3.5-<4.0 4.0-<4.5 4.5-<5.0 5.0-<5.5 5 15 27 34 22 5.5-<6.0 6.0-<6.5 6.5-<7.0 7.0-<7.5 7.5-<8.0 14 7 2 4 1 a) What proportion of the observations are less than 5 ?

Part C Give systematic names for the following compounds. CuF2 Spell out the full name of the compound. copper(II) fluoride Part D BaS Spell out the full name of the compound. Part E BeBr2 Spell out the full name of the compound.

and blue spheres representing the anions in each. Which of the following consistent with each drawing? (Figure 1)

Measurement and Matter Distinguishing solid, liquid and gas phases of a pure substance There are three sets of sketches below, showing the same pure molecular compound (water, molecular formula H2O) at three different temperatures. The sketches are drawn as if a sample of water were under a microscope so powerful that individual atoms could be seen. Only one sketch in each set is correct. Use the slider to choose the correct sketch in each set. You may need the following information: melting point of H2O: 0.0°C boiling point of H2O: 100.0°C

Which compound has 10 electrons counted towards the octet rule around its central atom? Select the correct answer below: CH₄ SF₄ BeCl₂ CO₂

is a measure of disorder or randomness. Entropy Enthalpy Calorimetry Internal energy Hess's law

A reaction below produced nickel tetracarbonyl, Ni(CO)4 in a 88% yield. Assuming sufficient nickel metal was used, what mass of carbon monoxide, CO, was added to the reaction if the actual yield of product, Ni(CO)4, was 185 g? Hint: Calculate the theoretical yield of nickel tetracarbonyl from the percent yield and work backwards from there. 4 CO(g)+Ni(s) -> Ni(CO)4(l) - For CO, 28.0 g / mol - For Ni(CO)4, 170.7 g / mol

Measurement and Matter Identifying the parts of an atom 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 electron (1) — (choose one) V (choose one) v — — 0 1.0 A neutron — — (choose one) v (choose one)

What is the size of the beakers used to make the voltaic cells in this lab? What is the volume of each solution used to construct the voltaic cells in this lab?

Atoms, Ions and Molecules Identifying oxoanions Complete the following table: two polyatomic anions name chemical formula nitrite anion SO4^2-

Complete this table. name empirical formula --------------------------------------- potassium iodide 1 copper(I) sulfide

What is any large molecule capable of triggering an immune response called? Macrophage Antigen Hapten Antibody

Question 46 Which of the following is not addressed in a Hazard Analysis and Critical Control Point (HACCP) program? a. food ordering and receiving protocols b. directions for cooking dishes c. cleaning and disinfecting of kitchen surfaces and utensils d. food storage procedures e. determining which diets should be offered in a facility

What type of bond is formed by the direct overlap of hybrid orbitals? Select the correct answer below: A σ bond A π bond Either a σ or a π bond An ionic bond

The radioactive substance cesium-137 has a half-life of 30 years. The amount A(t) (in grams) of a sample of cesium-137 remaining after t years is given by the following exponential function. A(t)=523(1/2)^(t/30) Find the initial amount in the sample and the amount remaining after 80 years. Round your answers to the nearest gram as necessary.

What are the ions in CuSO4? CuS2+ and O4^2- Cu2- and SO4^2+ Cu+ and SO4^2- Cu2+ and SO4^2-

Molarity is equal to what? moles / liters molecules/ liters

A Bronsted acid-base reaction is a form of proton transfer.

Why is -diol part of this compound's name? There are two - OH groups present There are two carbon atoms in the chain Diol is always written when an -OH group is present The compound contains two H atoms

Write -6.722 × 10^-2 as a decimal.

Using standard heats of formation, calculate the standard enthalpy change for the following reaction. 2 C2H6(g) + 7 O2(g) -> 4 CO2(g) + 6 H2O(g) ΔHrxn° = □ kJ

When NO(g) reacts with O2(g) according to the following reaction, 57.1 kJ of energy are evolved for each mole of NO(g) that reacts. Complete the following thermochemical equation. ΔH=NJ(g)+O2(g) → 2 NO2(g) ΔH=? ? kJ

Question 8 Which electrons would have the greatest effective nuclear charge? a. the valence electrons in aluminum b. the valence electrons in fluorine c. the se will have the same effective nuclear charge d. the valence electrons in phosphorus

A chemistry graduate student is given 450 mL of a 1.20 M chlorous acid (HClO2) solution. Chlorous acid is a weak acid with Ka=1.1 x 10^-2. What mass of KClO2 should the student dissolve in the HClO2 solution to turn it into a buffer with pH=2.51? You may assume that the volume of the solution doesn't change when the KClO2 is dissolved in it. Be sure your answer has a unit symbol, and round it to 2 significant digits.

Requirement 1. Journalize the year-end adjusting entry for bad debts on the basis of the aging schedule. Show the T-account for the Allowance for Bad Debts at December 31, 2025. Begin by determining the target balance of Allowance for Bad Debts by using the age of each account. Age of Accounts 1-30 Days 31-60 Days 61-90 Days Over 90 Days Total Balance Accounts Receivable 80,000 45,000 25,000 5,000 Estimated percent uncollectible 0.9% 3.0% 8.0% 46.0% Estimated total uncollectible Journalize the year-end adjusting entry for bad debts on the basis of the aging schedule. (Record debits first, then credits. Select the explanation on the last line of the journal entry table.) Date Accounts and Explanation Credit Dec. 31 Show the T-account for the Allowance for Bad Debts at December 31, 2025.

Fill in the blank. An unsaturated solution is one that a) contains no solute. b) has no double bonds. c) contains the maximum concentration of solute possible, and is in equilibrium with undissolved solute. d) has a concentration lower than the solubility. e) contains more dissolved solute than the solubility allows.

A non-functional enzyme which needs a cofactor is called a(n) .

Fill in the information missing from this table: Some electron subshells subshell principal quantum number n angular momentum quantum number l maximum number of electrons 5 p 2 s 4 f

Using the following conversion factors: 1 mol = MWing(2 d . g) = 6.022 E / 23 molecules = 22.414 L gas at STP How many atoms of Cl are in 347 g of SOCl2(MW=118.96 SOCl2)? (Express final answer as 'atoms Cl')

square → CaCl2(s)

C4H8O + O2 → CO2 + H2O

Most vegetables are naturally low in fat and energy.

What is meant by the term metabolic water?

How much heat is produced when 68.5 grams of Fe2O3 react? Be sure your answer has the correct number of significant figures.

Arrange the gases from most dense to least dense at a given temperature and pressure. Most dense Least dense Answer Bank SF6 F2 SO2 CH4 NH3

Write the balanced molecular equation for the reaction that occurs. Include the physical states of matter for each substance in the equation.

Minimum inhibitory concentration is Highest concentration of a drug with the lowest toxic dose to the host Smallest concentration of a drug with the highest toxic dose to the host Highest dilution of a drug that inhibits microbial growth Lowest dilution of a drug that inhibits microbial growth

Question 1 Define oxidation, reduction, and oxidation number. Describe how oxidation and reduction affect the oxidation number of an element.

If you can correctly explain to me at least 3 things wrong with this data table, you will receive 5 extra credit points.

pKa = 4.76, 3.00 M NaOH, and water. How many grams of acetic acid will be needed to prepare the 500 mL buffer? Note that the given concentration of acetate refers to the concentration of all acetate species in solution. mass: g

Predicting the relative electronegativities of atoms Re-order each list of elements in the table below, if elements elements in order of decreasing electronegativity As, F, N F, O, C Just output the content of the question, DO NOT output additional information or explanations.

Gaseous ethane (CH3CH3) reacts with gaseous oxygen gas (O2) to produce gaseous carbon dioxide (CO2) and gaseous water (H2O). If 8.24 g of carbon dioxide is produced from the reaction of 5.41 g of ethane and 27.8 g of oxygen gas, calculate the percent yield of carbon dioxide. Round your answer to 3 significant figures.

Math the pollutants with effects or other significant aspects A. Salinity B. Alkalinity C. Acidity D. Nitrate 1. Excessive productivity 2. Cake enter from pyrite or from the atmosphere 3. Osmotic effects on organisms 4. From soils and mineral strata

For the reaction 2 Hg(l)+O2(g) -> 2 HgO(s), ΔH=-43 kcal / mol. (a) Does entropy increase or decrease in this process? (b) Is this process spontaneous? Which reaction is faster, one with Eact =+10 kcal / mol or one with Eact =+5 kcal / mol ? Explain. Why does increasing concentration generally increase the rate of a reaction? If a catalyst changes the activation energy of a forward reaction from 28.0 kcal / mol to 23.0 kcal / mol, what effect does it have on the reverse reaction? For the reaction 2 H2(g)+2 C(s) -> H2C=CH2(g), ΔG=+16.3 kcal / mol at 25°C (a) Is the reaction of hydrogen with carbon to yield ethylene spontaneous at 25 C ? (b) Is it possible to find a catalyst for the reaction of hydrogen with carbon at 25 C ? Write the equilibrium equations for the following reactions, and tell whether reactants or products are favored in each case. (a) S2(g)+2 H2(g) <=> 2 H2S(g) K=2.8 x 10^21 (b) CO(g)+2 H2(g) CH3OH(g) K=10.5 (c) AgCl(s)+H2O(l) <=> Ag+(aq)+Cl^-(aq) K=1.3 x 10^-23

Ejercicios propuestos Formulación con reacción 35.- Una muestra de 1.000 g del compuesto XCl2 se trató con exceso de AgNO3, recuperándose todo el cloro como cloruro de plata con un peso de 1.280 g. ¿Cuál es la masa atómica experimental del elemento X?

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?

Submitting an external tool Question Consider the reaction described by the following chemical equation. 2 Ag2 S(s)+2 H2 O(l) -> 4 Ag(s)+2 H2 S(g)+O2(g) ΔHrxn^°=595.5 kJ/mol The change in enthalpy for this reaction can be determined theoretically by using the standard enthalpies of formation for the species involved. ΔHrxn^°=∑ n ΔHf products^°-∑ n ΔHf reactants^° What is the value for the standard enthalpy of formation for Ag(s) that would be used in the equation above? Provide your answer below: kJ / mol

A changeable aspect of an experiment is called a

Qual das seguintes vidrarias é mais precisa? A. Béquer de 250 ml ; B. Pipeta; C. Proveta.

What were the differences between solvents that dissolved aspirin the best/worst? Explain with structural comparisons and intermolecular forces.

If the TCA cycle doesn't require O2 as a reactant, why does the TCA cycle stop in the absence of oxygen? A. There's no oxygen to add to pyruvate to make acetyl CoA. B. The cell uses the O2 to generate the CO2 product made by the TCA cycle. C. NAD+ and FAD cannot be regenerated in the absence of O2 D. Without O2 the ETC will oxidize the acetyl CoA directly bypassing the TCA E. It doesn't stop in the absence of oxygen

Draw the structure of the neutral amine of Benedryl. Be sure to draw nonbonding electron pairs where applicable.

Consider the equilibrium reaction 4 A+B <=> 3 C Write the equation for the reverse reaction. reverse reaction: Write the equilibrium-constant expression in terms of [A] ;[B], and [C] for the reverse reaction. Answer Bank [B]^5 [C] [B]^3 [A]^3 [C]^4 [A] [A]^4 [B] [C]^3

Suppose that in a random selection of 100 colored candies, 22% of them are blue. The candy company claims that the percentage of blue candies is equal to 20%. Use a 0.05 significance level to test that claim. Identify the null and alternative hypotheses for this test. Choose the correct answer below. A. H0: p ≠ 0.2 H1: p=0.2 B. H0: p=0.2 H1: p>0.2 C. H0: P=0.2 H1: p ≠ 0.2 D. H0: P=0.2 H1: p<0.2

What do these two changes have in common? using a large magnet to remove pieces of iron from a junkyard sticking up a paper clip with a magnet Select all that apply. Both are changes of state. Both are caused by cooling? Both conserve mass. Both are only physical changes.

Choose the best answer using the periodic table. What is the name of this compound: Mg3 P2 magnesium phosphorus magnesium phosphide trimagnesium diphosphide phosphorus magnesium

Energy stored in a proton gradient is used to synthesize ATP from ADP and P during what process in oxidative phosphorylation? Glycolysis Fermentation Chemiosmosis Citric acid cycle

Question Some single displacement reactions involve one halogen replacing a less reactive halogen. Cl2, replaces iodine in NaI , producing I2 and NaCl . Write the balanced single displacement reaction below. - Do not include the states of the reactants or products.

Consider the proportionality below. PV ∝ nT What does this best represent? - Dalton's law - Charles's law - ideal gas law - combined gas law

Define the mole as a unit of measure Select the correct answer below the arimile furmitit the molar fies the stomic mass unit the mole

element #1 element #2 Forms ionic compound? empirical formula of ionic compound bromine potassium ○ yes no oxygen iodine ○ yes no oxygen potassium ○ yes no magnesium oxygen yes no

Solubility of Ionic Compounds Classify each of the compounds as soluble or not soluble: - manganese(II) nitrate - potassium carbonate - magnesium chloride

What is the emf of a cell consisting of a Pb2+ / Pb half-cell and a Pt / H+ / H2 half-cell if [Pb2+]=0.75 M, [H+]=0.063 M and PH2=1.0 atm? Round your answer to 2 significant digits.

Buffer #1 1. Measured pH of Buffer #1: 2. Total volume of Buffer #1: 35.0 mL 3. Determine the concentration of the acetic acid in this solution after mixing (include units): [HC2H3O2]= M Show work:

Which equation represents the first electron affinity of a chlorine atom? Cl^+(g) + e^- -> Cl(g) Cl^-(g) -> Cl(g) + e^- Cl(g) -> Cl^+(g) + e^- Cl(g) + e^- -> Cl^-(g)

Which of the following pH values are arranged from the most basic to the most acidic? a. 1,3,8,11,14 b. 2,5,7,10,11 c. 14,10,7,4,1 d. 14,10,7,1,3 e. 7,10,5,3,2

When 183. mg of a certain molecular compound X are dissolved in 50.0 g of benzene (C6H6), the freezing point of the solution is measured to be 5.2°C. Calculate the molar mass of X.

Riding a bicycle at 10-11 miles per hour uses 526 Calories in an hour. Be sure each of your answer entries has the correct number of significant figures. Convert this value to kilocalories. Report your answer in scientific notation. (1 Cal=1000 cal) kcal Convert this value to joules. Report your answer in scientific notation. Note: Reference the Conversion factors for non-SI units table for additional information. 2.20 x 10^2 J

Draw the Lewis dot diagram for a Be+ cation.

Fe2O3(s) + CO(g) →

Question 7 (1 point) A student is making a titration curve. To do so, they added 25.00 mL of 0.2470 M HCl to a flask. They then added 49.14 mL of 0.1170 M NaOH to the flask. What is the pH at this point in the titration curve? 3.1117 1.9343 2.2406 3.3436 1.6537

Gaseous methane (CH₄) will react with gaseous oxygen (O₂) to produce gaseous carbon dioxide (CO₂) and gaseous water (H₂O). Suppose 3.84 g of methane is mixed with 10. g of oxygen. Calculate the maximum mass of methane that could be used by this chemical reaction. Report your answer in g.

Two aqueous solutions of NaCl and AgNO3 are mixed. Write out what major chemical species will be present in the solution. Include physical states of matter.

Entry for uncollectible accounts Outlaw Bike Co. Is a wholesaler of motorcycle supplies. An aging of the company's accounts receivable on December 31 and a historical analysis of uncollectible accounts in each age category are given below. Age Interval Balance Estimated Uncollectible Accounts Percent Estimated Uncollectible Accounts Amount Not past due 620,000 1/2% 3,100 1-30 days past due 68,200 3% 2,046 31-60 days past due 31,000 8% 2,480 61-90 days past due 22,300 16% 3,568 91-180 days past due 16,100 39% 6,279 Over 180 days past due 11,800 80% 9,440 Total 769,400 26,913 Assume that the allowance for doubtful accounts for Outlaw Bike Co. had a debit balance of 4,845 as of December 31. Journalize the adjusting entry for uncollectible accounts as of December 31. If an amount box does not require an entry, leave it blank.

What is the proper name for MgF2? Multiple Choice magnesium fluoride magnesium (I) fluoride magnesium (II) fluoride magnesium difluoride monomagnesium difluoride

Which of the following is not a valid Lewis symbol? I II III IV

Com base nos conceitos sobre droga e produto natural, marque a opção que contenha uma distinção e uma semelhança entre eles, respectivamente: A Pode ter uma origem completamente sintética / possui atividade farmacológica ou biológica. B Originalmente obtido de um organismo vivo / pode ter uma origem completamente sintética. C Sofre processos de coleta, preparo e conservaçâo / pode ter uma origem completamente sintética. D Possui atividade farmacológica ou biológica / originalmente obtido de um organismo vivo. E Pode ter uma origem completamente sintética / sofre processos de coleta, preparo e conservaçāo.

An ion contains 1 nitrogen atom and 2 hydrogen atoms. It has an H-N-H bond angle of approximately 105°. Which row is correct? number of lone pairs around N in ion overall charge on ion ---------------------------------------------------------------- A 1 +1 B 2 +1 C 1 -1 D 2 -1

A student dissolves 6.7 g of sucrose (C12H22O11) in 200 mL of a solvent with a density of 0.91 g/mL. The student notices that the volume of the solvent does not change when the sucrose dissolves in it. Calculate the molarity and molality of the student's solution. Round both of your answers to 2 significant digits.

Question 21 (2 points). A type of fire sprinkler system where all the sprinkler heads become activated when fire is detected in even just one location is a system. 1) wet-pipe system 2) dry-pipe system 3) deluge system 4) antifreeze system

Consider images (a) - (d) below. Rank the images in terms of the relative strength of HX as an acid from most acidic at the top to least acidic (neutral) at the bottom.

Homework 4 Question 1 of 23 (1 point) I Question Attempt: 1 of 3 Six different aqueous solutions are represented in the beakers below, and their total noted. The solvent molecules are omitted for clarity. Part 1 of 5 Which solution has the highest molarity? Select the single best answer. Solution B Solution A Solution F Solution E Part 2 of 5 Which solutions have the same molarity? Check all that apply. Solutions C, D, and E Solutions A and F Solutions A and E Solutions A, B, and E None of the above

Question 3 To which category does the molecule below belong? alkenes aromatic hydrocarbons alkynes alkanes Question 4 Sucrose is an example of a monosaccharide. disaccharide. fruit sugar. polysaccharide.

Which of the following is an example of a hazard statement? a) "Danger" b) "Highly flammable liquid and vapor. May cause liver and kidney damage" c) "Do not handle until all safety precautions have been read and understood" d) "Wear protective gloves"

Question 19 0 pts Refer to the reaction: C2H4 + 3 O2 -> 2 CO2 + 2 H2O How many moles of oxygen are required for the complete reaction of 45 g of C2H4? 4.8 0.64 1.3 x 10^2 8.0 112.5

Complete the following table, which lists information about the measured acid dissociation constants of three unknown weak acids. Note: be sure each number you put in the table has the correct number of significant digits. acid (Ka) (mathbfp Ka) relative strength A ПI 9.006 B 10.4 C 4.50

¿Cuál de las siguientes afirmaciones están asociadas a velocidades de reacción lentas? I. moléculas de reactantes con enlaces fuertes. II. alta energía de activación. III. un alto porcentaje de orientaciones de colisión que pueden producir una reacción.

Calculate the number of molecules in 5.00 moles H2S. Express your answer numerically in molecules.

4.1 Write the symbols for the following elements: a. copper b. platinum c. calcium d. manganese e. iron f. barium g. lead h. strontium

([Delta c][Delta c])/([0.159-Delta c])=4.60 cdot 10^-4

Calculate the H^+ ion concentration in a solution with a pH of 3.85.

Calculate the mass of butane needed to produce 73.0 g of carbon dioxide. Express your answer to three significant figures and include the appropriate units.

Assuming equal concentrations and complete dissociation, arrange these aqueous solutions by their freezing points. Highest freezing point Lowest freezing point NH4Br K3PO4 K2CO3

Choose the best description of how a substrate binds to an enzyme active site. A. The substrate bonds covalently to the active site. B. The substrate binds to the active site if its geometry and shape fit the geometry of the active site. C. The substrate binds to the active site if there are strong enough intermolecular forces attracting the substrate to the active site. D. The substrate binds to the active site if the geometry fits and there are sufficient intermolecular forces attracting the substrate to the active site.

What is the mass of a sulfur tetrafluoride molecule?

The average human generates approximately his or her weight in ATP every day. A resting person uses about 25% of this in ion transport-mostly via the Na^+ - K^+ ATPase. Part A About how many grams of Na^+ will a sedentary 90-kg person pump across membranes in a day? Express your answer in grams to two significant figures. Part B About how many grams of K^+ will a sedentary 90 - kg person pump across membranes in a day?

We commonly see condensation on cold beverage containers. Water vapor is condensing on the surface. 2. What is the property of the surface that would cause water to condense on it? 3. What type of temperature (a term you learned) does the surface need to equal for condensation to occur?

Write the balanced NET ionic equation for the reaction when Pb(NO3)2 and RbCl are mixed in aqueous solution. If no reaction occurs, simply write only NR. Be sure to include the proper phases for all species within the reaction.

Elements that have six electrons in the highest-energy p sublevel in their ground state are called E) halogens D) alkali metals A) noble gases B) transition metals C) alkaline earth metals

Question 18 0.5 pts Before entering the metabolic pathways, amino acids first face - removal of their nitrogen-containing amino group - removal of their nitrogen - conversion to protein - condensation of their bonds - removal of their acetyl group

Calculate a single dose for this medication order.

The number of units needed to satisfy sales and provide the desired ending inventory is shown on the budget.

Multiple Choice Question The hydrocarbon mixture that is composed of alkanes, cycloalkanes, and some aromatic hydrocarb gasoline kerosene natural gas petroleum

Please note that "geometry" refers to the molecular or ionic geometry. A. What is the electron-pair geometry for Be in BeCl2 ? There are lone pair(s) around the central atom, so the geometry of BeCl2 is . B. What is the electron-pair geometry for Si in SiCl4 ? There are lone pair(s) around the central atom, so the geometry of SiCl4 is .

When the temperature of a gas is increased within a closed container, pressure increases due to which of the following? A The gas turns into a liquid. B The frequency of collisions between molecules and the container walls decreases. C The frequency of collisions between molecules and the container walls increases. D The spaces between the molecules of gas decrease.

Calculate energy required to heat 201.0 g of iron from -3.2°C to 6.8°C. Assume the specific heat capacity of iron under these conditions is 0.449 J · g.

Chemical Reactions Limiting reactants Gaseous methane (CH4) will react with gaseous oxygen (O2) to produce gaseous carbon dioxide (CO2) and gaseous water (H2O). Suppose 0.16 g of methane is mixed with 0.205 g of oxygen. Calculate the maximum mass of water that could be produced by the chemical reaction. Round your answer to 3 significant digits. g × 10

Which of the following is less basic than acetylide. A. BuLi B. NaNH2 C. NaOCH3 A and C B and C

Question 7 Find the last term (or the c ) to make the trinomial into a perfect square: [ x^2+frac65 x+frac925 ] When this is factored, it becomes:

Question 5 Identify the following reaction: NH4OH ⇌ NH3 + H2O dehydration synthesis reaction reversible reaction dehydration synthesis reaction

4 is the first excited state.

Below is an energy diagram, similar to that in Figure 1. Hint: Refer back to Figure 1 for guidance. a. Based on the starting atom in Models 1, 2, and 3 of Figure 3, place and label the electrons a, b, and c on the energy diagram above. b. Draw and label arrows on the diagram that correspond to the electron transitions shown in Models 1, 2, and 3. Make sure to consider which direction the arrow should be pointing. c. Are the electronic transitions drawn in part b corresponding to an absorption or an emission of a photon? d. Using the ionization energies provided in Question 12, calculate the energy (in J) that would be required to promote electron b to the same energy level as electron c.

The gram-formula mass of (NH4)2CO3 is (A) 96.0 g / mol (B) 78.0 g / mol (C) 64 g / mol (D) 46 g / mol

b. If the molarity of the based added from the buret was 0.200 M , determine the volume of the base (in ml required to reach the end point of this titration.

What is the coefficient in front of Na2 S when the chemical equation is correctly balanced Al(NO3)3+ Na2 S -> Al2 S3 + NaNO3

B B^3+ NO3^- K, S What is the formula name?

Draw the major product of this reaction. Ignore inorganic byproducts and CO2. Q KMnO4, H3O+

A chemical reaction takes place inside a flask submerged in a water bath. The water bath contains 6.30 kg of water at 35.1°C. During the reaction 10 kJ of heat flows out of the flask and into the bath. Calculate the new temperature of the bath. Assume the specific heat capacity of water is 4.185 J/g · °C.

Predicting the products of dissolution The names and chemical formulae of some chemical compounds are written in the first two columns of the table below. Each compound is soluble in water. Imagine that a few tenths of a mole of each compound is dissolved in a liter of water. Then, write down in the third column of the table the chemical formula of the major chemical species that will be present in this solution. For example, you know water itself will be present, so you can begin each list with the chemical formula for water (H2O). Note: "major" chemical species are those present in concentrations greater than 10^-6 mol / L. compound formula major species present when dissolved in water --------- glucose C6H12O6 isopropanol C3H8O nitrous oxide N2O

Imagine you are sitting in a room with a volume of 27000 liters and a temperature of 72°F. The total air pressure is 785 mm Hg, and the partial pressure from oxygen is 21% of the total pressure. How many grams of oxygen are in the room? amount of oxygen: grams Enter numeric value

The combustion of octane, C8H18, proceeds according to the reaction shown. 2 C8H18(l)+25 O2(g) -> 16 CO2(g)+18 H2O(l) If 506 mol of octane combusts, what volume of carbon dioxide is produced at 25.0°C and 0.995 atm? V= L

The length of human pregnancies is approximately normal with mean μ=266 days and standard deviation σ=16 days. Complete parts (a) through (f). (a) What is the probability that a randomly selected pregnancy lasts less than 260 days? The probability that a randomly selected pregnancy lasts less than 260 days is approximately (Round to four decimal places as needed.)

Consider the following samples of gas: - sample composition pressure temperature - A 1.1 mol Ne(g) 2.9 atm 291 °C - B 1.4 mol Ne(g) 2.9 atm 320 °C - C 1.6 mol Ne(g) 2.9 atm 258 °C - sample composition pressure temperature - D 1.8 mol Ar(g) 2.5 atm 32 °C - E 2.3 mol He(g) 2.5 atm 32 °C - F 1.6 mol Ne(g) 2.5 atm 32 °C Select the set of graphs below that show the distributions of the speed of the atoms in each sample.

If 4.9 kg of CO2 are produced during a combustion reaction, how many molecules of CO2 would be produced?

Calculate the standard-state entropy for the following reaction: 1 CH4(g) + 2 O2(g) -> 1 CO2(g) + 2 H2O(l) (If applicable, coefficients of one have been included for clarity.) The standard entropy values are given in the table. Formula S° J /(K · mol) CO2(g) 214 H2O(l) 189 CH4(g) 186 O2(g) 205 Express your answer with the appropriate units.

PEX Solute Gradients and Their Impact on Urine Concentration Pre-lab Quiz 2 The maximum solute concentration refers to the amount of solutes O in Bowman's capsule. O in the interstitial space. O in the urine. O in the plasma. Check Answer 2 of 4 Prev Ask my instructor

State H₀ and Hₐ in words and in symbols. Then determine whether the hypothesis test is left-tailed, right-tailed, or two-tailed. Explain your reasoning. Sketch a normal sampling distribution and shade the area for the P-value. A report claims that lung cancer accounts for at most 39% of all cancer diagnoses. State the null hypothesis in words and in symbols. The null hypothesis expressed in words is the proportion of cancer diagnoses attributable to lung cancer is at most 39%. The null hypothesis is expressed symbolically as H₀: P ≤ 0.39.

There are two steps in the usual industrial preparation of acrylic acid, the immediate precursor of several useful plastics. In the first step, calcium carbide and water react to form acetylene and calcium hydroxide: CaC2(s) + 2 H2O(g) → C2H2(g) + Ca(OH)2(s) ΔH = -414 kJ In the second step, acetylene, carbon dioxide and water react to form acrylic acid: 6 C2H2(g) + 3 CO2(g) + 4 H2O(g) → 5 CH2CHCO2H(g) ΔH = 132 kJ Calculate the net change in enthalpy for the formation of one mole of acrylic acid from calcium carbide, water and carbon dioxide from these reactions. Round your answer to the nearest kJ.

24 What are the 10 numerical prefixes used in naming molecules? Bonus: What was the phonetic memory device we used for these molecules?

Classify heat capacity and specific heat capacity as an extensive or intensive property. Hint heat capacity (select) Solution specific heat capacity (select)

What is the empirical formula for a compound containing 38.8% carbon, 16.2% hydrogen, and 45.1% nitrogen? CH2 N C40 H16 N45 C3 H16 N3 CH5 N

of the known chemical elements are displayed in the periodic table.

A 50.0 g sample of an unknown compound contains 14.19 g Na , 19.76 g O , and 16.05 g Cr . What is the percent composition of Na in the compound? [?]% Na

What is the molar mass of this compound? C4H10 Remember to round to the hundredths place from the periodic table. 34.00 g / mol 32.00 g / mol 58.14 g / mol 485.20 g / mol

Which of the following aqueous solutions will not be more soluble under acidic conditions? A Ag2SO4 B ZnF2 C Mg(OH)2 D CuBr

Water is a polar solvent and hexane (C6H14) is a nonpolar solvent. In which solvent is each of the following, which is found or used in the body, more likely to be soluble? Drag the appropriate substances to their respective bins. - riboflavin (vitamin B2), polar - NaHCO3 (baking soda), ionic - linoleic acid (lipid), nonpolar - canola oil, nonpolar Soluble in water Soluble in hexane

If 10.0 mL of 0.20 M NaOH is added to 50.0 mL of 0.10 M HCl, what will be the pH of the resulting solution? - Round your answer to two decimal places. Provide your answer below: pH=

You have 2.2 mol Xe and 3.0 mol F2, but when you carry out the reaction you end up with only 0.25 mol XeF4. What is the percent yield of this experiment? Xe(g) + 2 F2(g) -> XeF4(g)

Where does synthesis of the product begin in Transcription?

What is the molality of a solution of 8.75 g urea, CO(NH2)2 dissolved in 600.0 g water?

In the laboratory a student finds that it takes 129 Joules to increase the temperature of 12.9 grams of solid sulfur from 23.6 to 38.1 degrees Celsius. The specific heat of sulfur calculated from her data is J / g°C.

Match the correct conjugate acid formula to its base. Hint: Not all answer choices will be used. H2O H3O+ HCO3- H2CO3 SO4^2- HSO4^- ClO2^-

Draw a Lewis structure for SeBr2O.

Cal tends to fall asleep at the drop of a hat-while watching television, eating, and even driving. He would most likely be diagnosed with: circadian rhythm disorder. insomnia disorder. hypersomnolence disorder. narcolepsy.

Question 1 (1 point) Which of the following control techniques to avoid hazardous chemicals providing personal protective equipment to workers? - Administration control - User control - Source control - Path control Question 2 (1 point) Which of the following control techniques to avoid hazardous chemicals involves capturing, guarding, enclosing, insulating, or isolating a suspected hazard? - Source control - Path Control - User Control - Administration Control Question 3 (1 point) Hazard checklist for workplace layout design may contain one of the following items: - Place the hazardous machines at the entry of the plant. - Cover or guard any moving parts of machinery that could cut a worker or fly off. - Place the hazardous machines so that they are visible from easily accessing places. Question 4 (1 point) The product recall, which is the final remedial action as a result of recognizing a real or potential hazard after a device, structure, or system has been put into operation, must be taken for one of the following reasons: - The subsequent costs to maintain the product are too high. - The product does not live up to its advertised claims with regard to safety. - The company's high level management decides to take this course of action.

From the Lewis structures of the species given, pick all of those in which the central atom obeys the octet rule.

A mixture of He, N2, and Ar has a pressure of 29.8 atm at 28.0°C. If the partial pressure of He is 2371 torr and that of Ar is 967 mm Hg, what is the partial pressure of N2? PN2= atm

4. Morphine is a natural alkaloid derived from the opium poppy and a commonly used analgesic for moderate to severe pain. Heroin is a semi-synthetic opioid, created in the laboratory by acylating morphine. Heroin is more potent than morphine and passes through the blood-brain barrier more readily. More lipophilic (nonpolar) compounds are known to pass through the blood-brain barrier. Examining the structures of morphine and heroin depicted below, why does heroin pass through the blood-brain barrier more easily than morphine? (Hint: Identify the difference(s) between these two structures. How does that difference affect the blood-brain barrier?)

Cell phone production engineers have noted that among a group of 138 customers aged 14-23 who send more text messages tend to use a higher percentage of their phone's memory. What are the explanatory variable and response variable for this relationship? ○ Explanatory variable: age of customer Response variable: percentage of phone memory used ○ Explanatory variable: percentage of phone memory used Response variable: age of customer ○ Explanatory variable: number of text messages sent Response variable: percentage of phone memory used ○ Explanatory variable: percentage of phone memory used Response variable: number of text messages sent

Balance the following equation with the smallest whole number coefficients. When balanced, what is the coefficient for B (in the reactants)? Sc2O3 + ... B → ScB2 + ... BO a) 1 b) 3 c) 5 d) 7 e) 9

The average bond order is the number of bonds between two atoms taking into account resonance. Draw a Lewis structure for nitryl chloride and answer the questions below. 1. There are equivalent Lewis structures for NO2Cl. (number) 2. The average N - O bond order is

The length of a covalent bond depends upon the size of the atoms and the bond order. For each pair of covalently bonded atoms, choose the one expected to have the shorter bond length. P-1 or P-Br C-Br or P-Br

The first row has been completed for you. atom subshell from which electron removed to form +1 cation subshell to which electron added to form -1 anion --------- H 1 s 1 s He P Ar

Measurement and Matter Distinguishing solid, liquid and gas phases of a pure substance There are three sets of sketches below, showing the same pure molecular compound (hydrogen chloride) at different temperatures. The sketches are drawn as if a sample of hydrogen chloride were under a microscope. Only one sketch in each set is correct. Use the slider to choose the correct sketch in each set. You may need the following information: melting point of HCl: -114.8°C boiling point of HCl: -85.1°C A B C -143 °C -95 °C -53 °C

How many valence electrons does an atom of boron, Z=5, have?

According to the following reaction, how many grams of sulfur trioxide will be formed upon the complete reaction of 21.4 grams of oxygen gas with excess sulfur dioxide? sulfur dioxide (g)+ oxygen (g) → sulfur trioxide (g) Mass = grams sulfur trioxide

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