Question

The reaction 2A → B is first order in A with a rate constant of 2.8 × 10⁻² s⁻¹ at 80°C. How long (in seconds) will it take for A to decrease from 0.650 M to 0.130 M?

 

Answer 1

k×t = ln$\frac{A_0}{A_t}$

2.8×10^-2 × t = ln $\frac{0.650}{0.130}$

t = (100/2.8) ln 5

t = (100×1.60)/2.8

t = 57.14sec