For the non-stoichiometric reaction 2A + B → C + D, the following kinetic data were obtained in three separate experiments, all at 298 K.
The rate law for the formation of C is:
| Initial Concentration (A) | Initial Concentration (B) | Initial rate of formation of C (mol L⁻¹s⁻¹) |
|---|---|---|
| 0.1 M | 0.1 M | 1.2 × 10⁻³ |
| 0.1 M | 0.2 M | 1.2 × 10⁻³ |
| 0.2 M | 0.1 M | 2.4 × 10⁻³ |
The rate law for the formation of C is:
- (A)dc/dt = k[A][B]²
- (B)dc/dt = k[A]✓ Correct
- (C)dc/dt = k[A][B]
- (D)dc/dt = k[A]²[B]
Answer: (B)
Solution
Compare experiments where one concentration is held fixed. Between the first two, is constant while doubles, yet the rate is unchanged, so the order in is zero. Between the first and third, is constant while doubles and the rate doubles, so the order in is one. The rate law is therefore .
JEE Main · 2014 · 06 Apr 2014 · Offline · Single correct option