Write a rate equation showing the dependence of rate in reactant concentrations for each of the following elementary reactions.
a. CS2---> CS + S
b. CH3Br + OH- --> CH3OH + Br-
A. k[CS2][S]
B. k[CH3][Br-][OH-]
To determine the rate equation for each of the given elementary reactions, we need to consider the stoichiometry of the reaction and the order of each reactant.
a. The balanced chemical equation for the reaction is:
CS2 ---> CS + S
From this equation, we can see that one molecule of CS2 reacts to form one molecule of CS and one molecule of S. Therefore, the rate of the reaction depends only on the concentration of CS2. The rate equation for this reaction is:
Rate = k[CS2]
where k is the rate constant.
b. The balanced chemical equation for the reaction is:
CH3Br + OH- --> CH3OH + Br-
From this equation, we can see that one molecule of CH3Br reacts with one hydroxide ion (OH-) to form one molecule of CH3OH and one bromide ion (Br-). Therefore, the rate of the reaction depends on the concentrations of CH3Br, OH-, and Br-. The rate equation for this reaction is:
Rate = k[CH3Br][OH-][Br-]
where k is the rate constant.
In summary:
a. The rate equation for the reaction CS2 ---> CS + S is Rate = k[CS2]
b. The rate equation for the reaction CH3Br + OH- --> CH3OH + Br- is Rate = k[CH3Br][OH-][Br-]