a. What would be the concentration of dinitrogen pentoxide in the experiment described in Example 13.5 after 6.00 102 s? b. How long would it take for the concentration of N2O5 to decrease to 10.0%...

Acetaldehyde, CH3CHO, decomposes when heated. CH3CHO(g) CH4(g)Ã CO(g) The rate constant for the decomposition is 1.05Ã 103/(M1/2s) at 759 K and 2.14 Ã 102/(M1/2s) at 836 K. What...

A reaction believed to be either first or second order has a half-life of 20 s at the beginning of the reaction but a half-life of 40 s sometime later. What is the order of the reaction?

A plot of 1/[A] versus time for the hypothetical reaction A B+ C yields a straight line. a. What is the order of the reaction? b. If it took 57 s for the concentration to drop 40 percent from its...

A second-order decomposition reaction run at 550oC has a rate constant of 3.1 102 L/(mols). If the initial concentration of the reactant is 0.10 M, what is the concentration of this reactant after...

Urea, (NH2)2CO, can be prepared by heating ammonium cyanate, NH4OCN. NH4OCN (NH2)2CO This reaction may occur by the following mechanism: What is the rate law predicted by this mechanism? NH4 OCNNH3...

The reaction of water with CH3Cl in acetone as a solvent is represented by the equation CH3Cl H2O CH3OH + HCl The rate of the reaction doubles when the concentration of CH3Cl is doubled and it...

The reaction of methylacetate with water is shown by the equation below: CH3COOCH3(aq) + H2O CH3COOH(aq) + CH3OH(aq) The rate of the reaction is given by the rate law: Rate = k[H3O+][CH3COOCH3]

A study of the gas-phase oxidation of nitrogen monoxide at 25oC and 1.00 atm pressure gave the following results: 2NO(g)+ O2(g) NO2(g) a. What is the experimental rate law for the reaction above? b....

Draw and label the potential-energy curve for the reaction The activation energy for the reverse reaction is 23 kJ. ÎH and Ea on the diagram. What is the activation energy for the forward...

The decomposition of hydrogen peroxide is a first-order reaction: H2O2(aq) H2O(l) + 1 / 2 O2(g) The half-life of the reaction is 17.0 minutes. a. What is the rate constant of the reaction? b. If you...

A reaction of the form aA Products is second order with a half-life of 307 s. What is the rate constant of the reaction if the initial concentration of A is 1.87 1002 mol/L?

A possible mechanism for a gas-phase reaction is given below. What is the rate law predicted by this mechanism? (fast equilibrium) 2NOCI NOC NO2NOCI (slow)

By means of an example, explain what is meant by the term reaction intermediate.

The reaction 2A(g) A2(g) is being run in each of the following containers. The reaction is found to be second-order with respect to A. a. Write the rate law for the reaction. b. Which reaction...

A rate of reaction depends on four variables (Question 13.1). Explain by means of an example how the rate law deals with each of these variables.

Nitrogen dioxide, NO2, decomposes upon heating to form nitric oxide and oxygen according to the following equation: 2NO2(g) 2NO(g) + O2(g) At the beginning of an experiment, the concentration of...

Hydrogen sulfide is oxidized by chlorine in aqueous solution. H2S(aq) + Cl2(aq) S(s) + 2HCl(aq) The experimental rate law is Rate = k[H2S][Cl2] What is the reaction order with respect to H2S? with...

Iodide ion is oxidized to hypoiodite ion, IO, by hypochlorite ion, ClO, in basic solution. The equation is The following initial-rate experiments were run and, for each, the initial rate of...

Cyclopropane, C3H6, is converted to its isomer propylene, CH2PCHCH3, when heated. The rate law is first order in cyclopropane, and the rate constant is 6.0 104/s at 500oC. If the initial...

Ethyl chloride, CH3CH2Cl, used to produce tetraethyllead gasoline additive, decomposes, when heated, to give ethylene and hydrogen chloride. CH3CH2Cl(g) C2H4(g) + HCl(g) The reaction is first order....

Methyl isocyanide, CH3NC, isomerizes, when heated, to give acetonitrile (methyl cyanide), CH3CN. CH3NC(g) CH3CN(g) The reaction is first order. At 230oC, the rate constant for the isomerization is...

In the presence of excess thiocyanate ion, SCN, the following reaction is first order in chromium(III) ion, Cr3+; the rate constant is 2.0 106/s. Cr3+(aq) + SCN(aq) Cr(SCN)2+(aq) If 85.0% reaction...

The reaction A B + C is found to be zero order. If it takes 4.3 102 seconds for an initial concentration of A to go from 0.50 M to 0.25 M, what is the rate constant for the reaction?

The reaction 2NOCl(g) 2NO(g) + Cl2(g) has rate-constant values for the reaction of NOCl of 9.3 106/s at 350 K and 6.9 104/s at 400 K. Calculate activation energy for the reaction. What is the rate...

The rate of a particular reaction triples when the temperature is increased from 25oC to 35oC. Calculate the activation energy for this reaction.

A rate law is one-half order with respect to a reactant. What is the effect on the rate when the concentration of this reactant is doubled?

Ozone decomposes to oxygen gas. 2O3(g) 3O2(g) A proposed mechanism for this decomposition is What is the rate law derived from this mechanism? O3 2 + O (fast, equilibrium) slow)

A study of the decomposition of azomethane, CH3NNCH3(g) C2H6(g)+ N2(g) gave the following concentrations of azomethane at various times: Time [CH3NNCH3] 0 min. 1.50 102 M 10 min. 1.29 102 M 20...

The following reaction is important in the manufacture of sulfuric acid. At 900 K, 0.0216 mol of SO2 and 0.0148 mol of O2 are sealed in a 1.00-L reaction vessel. When equilibrium is reached, the...

A researcher put 0.400 mol PCl3 and 0.600 mol Cl2 into a 5.00-L vessel at a given temperature to produce phosphorus pentachloride, PCl5: What will be the composition of this gaseous mixture at...

a. Write the equilibrium-constant expression Kc for the equation b. Write the equilibrium-constant expression Kc when this reaction is written 2NO2(g) + 7H2(g)2NH3(g) +4H20(g) NO2(g) + 4H2(g) NH3(g)...

At high temperatures, a dynamic equilibrium exists between carbon monoxide, carbon dioxide, and solid carbon. At 850oC, Kc is 0.153. a. What is the value of Kp? b. If the original reaction system...

At 25oC in a closed system, ammonium hydrogen sulfide exists as the following equilibrium: a. When a sample of pure NH4HS(s) is placed in an evacuated reaction vessel and allowed to come to...

Gaseous acetic acid molecules have a certain tendency to form dimers. (A dimer is a molecule formed by the association of two identical, simpler molecules.) The equilibrium constant Kc at 25oC for...

Antimony(V) chloride, SbCl5, dissociates on heating to give antimony(III) chloride, SbCl3, and chlorine. A closed 3.50-L vessel initially contains 0.0125 mol SbCl5. What is the total pressure at...

A mixture initially consisting of 2 mol CO and 2 mol H2 comes to equilibrium with methanol, CH3OH, as the product: At equilibrium, the mixture will contain which of the following? a. less than 1 mol...

Gaseous acetic acid molecules have a certain tendency to form dimers. (A dimer is a molecule formed by the association of two identical, simpler molecules.) The equilibrium constant Kp at 25oC for...

Ammonium hydrogen sulfide, NH4HS, is unstable at room temperature and decomposes: You have placed some solid ammonium hydrogen sulfide in a closed flask. Which of the following would produce less...

An experimenter introduces 4.0 mol of gas A into a 1.0-L container at 200 K to form product B according to the reaction Using the experimenters data (one curve is for A, the other is for B),...

Write equilibrium-constant expressions Kc for each of the following reactions. a. N203(g)NO2(8) +NO(g 2NO(g)+O2(g) 2NO2(g) PC13(g) + 3NH3(g)-P(NH2)3(g) + 3HC(g) c. d.

Write equilibrium-constant expressions Kc for each of the following reactions. a. N2(g) 2H2g) N2H4(g) b. 2NOCI(g) 2N0(g) + Cl2(g) c. 2NO(g) 2H2(g)N2(8) 2H20(g)

Write equilibrium-constant expressions Kp for each of the following reactions: b. CS2(g) 4H2g)CH4(g) +2H2S(g) c. 4HCI(g) + O2(g) 2H2O(g) + 2C12(g)

Write equilibrium-constant expressions Kp for each of the following reactions: a. N204(g) 2NO2(g) d. 4NH3(g) +502(g)4NO(g) + 6H20(g)

A mixture of carbon monoxide, hydrogen, and methanol, CH3OH, is at equilibrium according to the equation At 250oC, the mixture is 0.096 M CO, 0.191 M H2, and 0.015 M CH3OH. What is Kc for this...

Iodine monobromide, IBr, occurs as brownish-black crystals that vaporize with decomposition: The equilibrium constant Kc at 100oC is 0.026. If 0.010 mol IBr is placed in a 1.0-L vessel at 100oC, what...

A 2.0-L reaction flask initially contains 0.10 mol CO, 0.20 mol H2, and 0.50 mol CH3OH (methanol). If this mixture is brought in contact with a zinc oxidechromium(III) oxide catalyst, the equilibrium...

Dinitrogen tetroxide, N2O4, is a colorless gas (boiling point, 21oC), which dissociates to give nitrogen dioxide, NO2, a reddish brown gas. The equilibrium constant Kc at 25oC is 0.125. What...

What are the moles of substances present at equilibrium at 450oC if 1.00 mol N2 and 4.00 mol H2 in a 10.0-L vessel react according to the following equation? The equilibrium constant Kc is 0.153 at...

A solution of barium hydroxide at 25C is 0.125 M Ba(OH)2. What are the concentrations of hydronium ion and hydroxide ion in the solution?

A solution has a hydroxide-ion concentration of 1.0 10-5 M at 25C. Is the solution acidic, neutral, or basic?

What is meant by the self-ionization of water? Write the expression for Kw. What is its value at 25C?

A solution contains 0.675 g of ethylamine, C2H5NH2, per 100.0 mL of solution. Electrical conductivity measurements at 20C show that 0.98% of the ethylamine has reacted with water. Write the equation...

What is meant by the pH of a solution? Describe two ways of measuring pH.

Aluminum chloride, AlCl3, reacts with trimethylamine, N(CH3)3. What would you guess to be the product of this reaction? Explain why you think so. Describe the reaction in terms of one of the acidbase...

Arrange each of the following in order of increasing acidity. You may need to use a couple of rules to decide the order for a given series. Explain the reasoning you use in each case. a. HBrO2,...

What is the pH of a neutral solution at 37C, where Kw equals 2.5 10-14?

Describe any thermochemical (heat of reaction) evidence for the Arrhenius concept.

Aqueous solutions of ammonia, NH3, were once thought to be solutions of an ionic compound (ammonium hydroxide, NH4OH) in order to explain how the solutions could contain hydroxide ion. Using the...

A strong monoprotic acid, with the molecular structure, is dissolved in a beaker of water. Which of the following pictures best represents the acid solution (water molecules have been omitted for...

A weak acid, HA, is dissolved in water. Which one of the following beakers represents the resulting solution? (Water molecules have been omitted for clarity.)

Define an acid and a base according to the BrnstedLowry concept. Give an acidbase equation and identify each species as an acid or a base.

Write the balanced reaction of hypochlorous acid, HOCl, with water to form hydronium ion and the conjugate base of HOCl. Identify each species as either an acid or a base.

Give the conjugate base to each of the following species regarded as acids. a. HPO42 b. H2S c. HNO2 d. H2AsO4

Complete each of the following equations. Then write the Lewis formulas of the reactants and products and identify each reactant as a Lewis acid or a Lewis base. a. AlCl3 + Cl b. I + I2

Coal and other fossil fuels usually contain sulfur compounds that produce sulfur dioxide, SO2, when burned. One possible way to remove the sulfur dioxide is to pass the combustion gases into a tower...

Write an equation in which H2PO3 acts as an acid and another in which it acts as a base.

Order each of the following pairs by acid strength, giving the weaker acid first. Explain your answer. a. HBrO4, HBrO3 b. HCO3, H2CO3 c. H2S, H2Te d. HBr, H2Se e. H3PO4, H3AsO4

A saturated solution of magnesium hydroxide is 3.2 10-4 M Mg(OH)2. What are the hydronium-ion and hydroxide-ion concentrations in the solution at 25C?

Describe four ways in which the BrnstedLowry concept enlarges on the Arrhenius concept.

A shampoo solution at 25C has a hydroxide-ion concentration of 1.5 10-9 M. Is the solution acidic, neutral, or basic?

An antiseptic solution at 25C has a hydroxide-ion concentration of 8.4 10-5 M. Is the solution acidic, neutral, or basic?

Obtain the pH corresponding to the following hydronium-ion concentrations. a. 1.0 108 M b. 5.0 1012 M c. 7.5 103 M d. 6.35 109 M

A sample of vinegar has a hydronium-ion concentration of 7.5 103 M. What is the pH of the vinegar?

Define an acid and a base according to the Lewis concept. Give a chemical equation to illustrate.

Obtain the pH corresponding to the following hydroxide-ion concentrations. a. 6.74 1011 M b. 5.8 105 M c. 3.4 1010 M d. 7.1 104 M

A solution of washing soda (sodium carbonate, Na2CO3) has a hydroxide-ion concentration of 0.0040 M. What is the pH at 25C?

A solution of lye (sodium hydroxide, NaOH) has a hydroxide-ion concentration of 0.050 M. What is the pH at 25C?

A wine was tested for acidity, and its pH was found to be 3.85 at 25C. What is the hydronium-ion concentration?

A detergent solution has a pH of 11.63 at 25C. What is the hydroxide-ion concentration?

Explain why an acidbase reaction favors the weaker acid.

A 1.00-L aqueous solution contained 6.78 g of barium hydroxide, Ba(OH)2. What was the pH of the solution at 25C?

Give two important factors that determine the strength of an acid. How does an increase in each factor affect the acid strength?

A solution is 0.25 M KOH. What are the concentrations of H3O+ and OH in this solution?

A solution is 0.35 M Sr(OH)2. What are the concentrations of H3O+ and OH in this solution?

A wine has a hydronium-ion concentration equal to 1.5 103 M. What is the pH of this wine?

A sample of lemon juice has a hydronium-ion concentration equal to 2.5 102 M. What is the pH of this sample?

A sample of apple cider has a pH of 3.15. What is the hydroxide-ion concentration of this solution?

A sample of grape juice has a pH of 4.05. What is the hydroxide-ion concentration of this solution?

Lactic acid, HC3H5O3, is found in sour milk, where it is produced by the action of lactobacilli on lactose, or milk sugar. A 0.025 M solution of lactic acid has a pH of 2.75. What is the ionization...

What is the pH of a buffer prepared by adding 30.0 mL of 0.15 M HC2H3O2 (acetic acid) to 70.0 mL of 0.20 M NaC2H3O2 (sodium acetate)?

What is the pH of a solution in which 15 mL of 0.10 M NaOH has been added to 25 mL of 0.10 M HCl?

An 80.0-mL sample of 0.200 M ammonia is titrated with 0.100 M hydrochloric acid. Kb for ammonia is 1.8 10-5. Calculate the pH of the solution at each of the following points of the titration: a....

An artificial fruit beverage contains 11.0 g of tartaric acid, H2C4H4O6, and 20.0 g of its salt, potassium hydrogen tartrate, per liter. What is the pH of the beverage? Ka1 = 1.0 103.

A solution is prepared from 0.150 mol of formic acid and enough water to make 0.425 L of solution. a. Determine the concentrations of H3O+ and HCOO in this solution. b. Determine the H3O+...

A quantity of 0.25 M sodium hydroxide is added to a solution containing 0.15 mol of acetic acid. The final volume of the solution is 375 mL and the pH of this solution is 4.45. a. What is the molar...

A quantity of 0.15 M hydrochloric acid is added to a solution containing 0.10 mol of sodium acetate. Some of the sodium acetate is converted to acetic acid, resulting in a final volume of 650 mL of...

A 0.150 M solution of NaClO is prepared by dissolving NaClO in water. A 50.0-mL sample of this solution is titrated with 0.100 M HCl. Calculate the pH of the solution at each of the following points...

Acrylic acid, whose formula is HC3H3O2 or HO2CCH=CH2, is used in the manufacture of plastics. A 0.10 M aqueous solution of acrylic acid has a pH of 2.63. What is Ka for acrylic acid?

A chemist wanted to determine the concentration of a solution of lactic acid, HC3H5O3. She found that the pH of the solution was 2.51. What was the concentration of the solution? The Ka of lactic...