Question

Using the following information, what are the values of the exponents in the rate expression, rate = k[A]x[B]y
initial concentration of A, initial concentration of B, rate

Experiment 1: 0.050M, 0.050M, 0.062M/sec
Experiment 2: 0.050M, 0.100M, 0.123M/sec
Experiment 3: 0.100M, 0.100M, 0.491M/sec

A) x = 2, y = 1
B) x = 1, y = 0
C) x = 1, y = 1
D) x = 0, y = 1

Answer 1

Answer:

The correct option is;

A) x = 2, y = 1

Explanation:

Here we have

$k[0.05]^x \cdot [0.05]^y = 0.062 \ M/sec$....................(1)

$k[0.05]^x \cdot [0.10]^y = 0.123 \ M/sec$....................(2)

$k[0.100]^x \cdot [0.100]^y = 0.491 \ M/sec$  ..............(3)

From experiment (1), (2) it is observed that [A] is held constant and [B] is doubled of which the rate is also observed to be doubled, therefore, when you double a reactant which result in the rate being doubled, the order of the reaction with respect to the reactant is order 1, therefore, y = 1.

Similarly between reaction (2) and (3) when the concentration of the reactant B is doubled and A is held constant the rate of the reaction is multiplied by a factor of 4, therefore, the reaction with respect to that reactant is order 2, therefore, x = 2.

Therefore, the correct option is x = 2, y = 1.