Q: For the reaction $$2NO (g) + O_2$ (g) \rightarrow 2NO_2 (g)$$, the rate law is $$\text{rate} = k[NO]^2[O_2$]. If $$the initial rate is $$0.017\ \mathrm{M/s}$$ when $$[NO] = 0.012\ \mathrm{M}$$ and $$[O_2$] = 0.017\ \mathrm{M}$$, what is the value of $$k$$?

$$6.9 \times 10^2$\ \mathrm{M}^{-2}\mathrm{s}^{-1}$$

Question 1

For the reaction $$\mathrm{N_2$ (g) + 3H_2 (g) \rightarrow 2NH_3 (g)}$$, if the rate of disappearance of $$\mathrm{H_2$} is$$ $$0.084\ \mathrm{M/s}$$, what is the rate of formation of $$\mathrm{NH_3$}$$?

Accepted Answer

$$0.056\ \mathrm{M/s}$$

Question 2

Given the rate law for the reaction $$2NO (g) + Cl_2$ (g) ightarrow 2NOCl (g) is$$ $$	ext{rate} = k[NO]^2[Cl_2$]$$, what is the overall order of the reaction?

Accepted Answer

Third order

Question 3

For the reaction $$A (aq) + 2B (aq) ightarrow C (aq)$$, the rate law is $$	ext{rate} = k[A][B]^2. If$$ $$[A] is $$doubled and $$[B] is $$tripled, by what factor does the rate increase?

Accepted Answer

18

Question 4

The decomposition of $$\mathrm{SO_2Cl_2} is $$first order with a rate constant $$k = 2.0 	imes 10$$^{-3}$$\ \mathrm{s}^{-1}. $$What is the half-life of the reaction?

Accepted Answer

$$693\ \mathrm{s}$$

Question 5

A sample of organic material contains $$15.9\% of $$the original carbon-14. If the half-life of carbon-14 is $$5730$$ years, estimate the age of the sample.

Accepted Answer

$$15,000$$ years

Question 6

For the reaction $$2NOBr (g) ightleftharpoons 2NO (g) + Br_2$ (g)$$, if $$K_c = 3.07 	imes 10^1$ at 24$$^\circ$$C, what is the equilibrium expression for K_c$?

Accepted Answer

$$K_c = \dfrac{[NO]^2[Br_2$]}{[NOBr]^2}$$

Question 7

If the initial concentration of $$\mathrm{SO_2Cl_2} is$$ $$1.00\ \mathrm{M}$$, how long will it take for the concentration to decrease to $$0.72\ \mathrm{M}$$? ($$k = 2.0 	imes 10$$^{-3}$$\ \mathrm{s}^{-1}$$, first order)

Accepted Answer

$$1650\ \mathrm{s}$$

Question 8

For the reaction $$2NO (g) + O_2$ (g) ightarrow 2NO_2 (g)$$, the rate law is $$	ext{rate} = k[NO]^2[O_2$]. If $$the initial rate is $$0.017\ \mathrm{M/s}$$ when $$[NO] = 0.012\ \mathrm{M}$$ and $$[O_2$] = 0.017\ \mathrm{M}$$, what is the value of $$k$$?

Accepted Answer

$$6.9 	imes 10^2$\ \mathrm{M}^{-2}\mathrm{s}^{-1}$$

Question 9

Given the Arrhenius plot $$y = -10759x + 26.769$$, what is the activation energy $$E_a in kJ/$$mol?

Accepted Answer

$$89.5\ \mathrm{kJ/mol}$$

Question 10

For the equilibrium $$4IBr (g) \rightleftharpoons 2I_2 (g) + 2Br_2 (g)$$, what is the equilibrium constant expression?

Accepted Answer

$$K = \dfrac{[I_2$]^2[Br_2$]^2}{[IBr]^4}$$

Question 11

For the reaction $$2H_2 (g) + CO (g) ightleftharpoons CH_3OH (g)$$, if $$K_c = 1.6 	imes 10^2$ at equilibrium, and there are 17.1$$ 	imes $$10^{-2}$$ moles of $$H_2$$ and $$3.46 	imes 10$$^{-3}$$ moles of CO$ in a 50.0$ L flask, how many moles of CH_3OH$ are present at equilibrium?

Accepted Answer

$$0.059$$ moles

Question 12

Which of the following changes will shift the equilibrium of the endothermic reaction $$\mathrm{N_2$ (g) + 3H_2 (g) \rightleftharpoons 2NH_3 (g)} to $$the right?

Accepted Answer

Increase temperature

Question 13

Which of the following is the correct equilibrium expression for $$2SiOBr_2 (g) \rightleftharpoons $$SiO_2$$ (g) + $$SiBr_4$$ (g)$$?

Accepted Answer

$$K = \dfrac{[$$SiO_2$$][$$SiBr_4$$]}{[$$SiOBr_2$$]^2}$$

Question 14

Which of the following acids is a strong acid?

Accepted Answer

HCl

Question 15

Which statement best describes the Brønsted-Lowry definition of acids and bases?

Accepted Answer

Acids are proton donors, bases are proton acceptors.

Question 16

A reaction has a rate constant of $$0.00122\ \mathrm{s}^{-1} at$$ $$77^\circC $$and $$0.228\ \mathrm{s}^{-1} at$$ $$177^\circC. $$What is the activation energy $$E_a$$ for the reaction?

Accepted Answer

$$52.1\ \mathrm{kJ/mol}$$

Question 17

For the reaction $$2NOBr (g) \rightleftharpoons 2NO (g) + Br_2$ (g)$$, a $$4.00 L $$vessel contains $$0.0148$$ moles of $$NOBr$$, $$0.0126$$ moles of $$NO$$, and $$0.0085$$ moles of $$Br_2 at $$equilibrium. What is the value of the equilibrium constant $$K_c$$?

Accepted Answer

$$0.307$$

Question 18

Which of the following is the conjugate base of $$HS^-$$?

Accepted Answer

$$S^{2-}$$

Chemical Kinetics, Chemical Equilibrium, and Acids & Bases: Study Notes

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