91Ó°ÊÓ

List the four variables or factors that can affect the rate of reaction.

Give at least two physical properties that might be used to determine the rate of a reaction.

The exponents in a rate law have no relationship to the coefficients in the overall balanced equation for the reaction. Give an example of a balanced equation and the rate law for a reaction that clearly demonstrates this.

The reaction $$3 \mathrm{I}^{-}(a q)+\mathrm{H}_{3} \mathrm{As} \mathrm{O}_{4}(a q)+2 \mathrm{H}^{+}(a q) \longrightarrow \mathrm{I}_{3}^{-}(a q)+\mathrm{H}_{3} \mathrm{AsO}_{3}(a q)+\mathrm{H}_{2} \mathrm{O}(l)$$ is found to be first order with respect to each of the reactants. Write the rate law. What is the overall order?

The rate of a reaction is quadrupled when the concentration of one reactant is doubled. What is the order of the reaction with respect to this reactant?

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?

The reaction \(\mathrm{A}(g) \longrightarrow \mathrm{B}(g)+\mathrm{C}(g)\) is known to be first order in \(\mathrm{A}(g) .\) It takes \(25 \mathrm{~s}\) for the concentration of \(\mathrm{A}(g)\) to decrease by one-half of its initial value. How long does it take for the concentration of \(\mathrm{A}(g)\) to decrease to one-fourth of its initial value? to one-eighth of its initial value?

Compare the half-life equations for a first-order and a second-order reaction. For which reaction order is the value of the half-life independent of the reactant concentration?

What two factors determine whether a collision between two reactant molecules will result in reaction?

Sketch a potential-energy diagram for the exothermic, elementary reaction $$\mathrm{A}+\mathrm{B} \longrightarrow \mathrm{C}+\mathrm{D}$$ and on it denote the activation energies for the forward and reverse reactions. Also indicate the reactants, products, and activated complex.