Question

For the reaction a + 2b → c under a given set of conditions, the initial rate is 0.190 m/s. What is the rate law for this reaction?

1) rate = k[a][b]²
2) rate = k[a][b]
3) rate = k[a]
4) rate = k[b]

Answer 1

The rate law for the given reaction is rate = k[a][b]², with the order of the reaction with respect to [a] being 0 and the order of the reaction with respect to [b] being 2. The rate constant, k, is equal to 0.190 m/s.

Step-by-step explanation:

The given reaction is a + 2b → c. To determine the rate law, we need to analyze the effect of the initial concentrations of reactants on the rate of the reaction. Based on the given information, we can see that doubling the concentration of reactant a does not change the rate, indicating that the order of the reaction with respect to [a] is 0. However, doubling the concentration of reactant b quadruples the rate, indicating that the order of the reaction with respect to [b] is 2. Therefore, the rate law for this reaction is rate = k[a][b]².

To find the rate constant, we can use the given initial rate and the initial concentrations of reactants. Plugging in the values, we get:

0.190 m/s = k[a][b]²

Substituting the initial concentrations of [a] and [b], we can solve for k:

0.190 m/s = k(1)(1)²

k = 0.190 m/s