Practicing Success

Target Exam

CUET

Subject

Chemistry

Chapter

Physical: Chemical Kinetics

Question:

The rate constant of a reaction 2N2O5 → 4NO2 (g) + O2 (g) is 3 x 10-5 s-1. If the rate of reaction is 2.4 x 10-5 mol L-1 s-1, then what is the concentration of N2O5 in mol/L?

Options:

1.4

1.2

0.04

0.8

Correct Answer:

0.8

Explanation:

Rate constant of a reaction, k = 3 x 10-5 s-1 

Therefore, it is a first order reaction.

r = k [N2O5]

2.4 x 10-5 mol L-1 s-1 = 3 x 10-5 s-1 x [N2O5]

 [N2O5] = \(\frac{2.4 × 10^{-5}}{ 3 × 10^{-5}}\) = 0.8 mol/L