Question

Observe the following reaction :

A(g) + 3B(g) ® 2C(g)

The rate of this reaction$\left\{ \frac{- d\lbrack A\rbrack}{dt} \right\}$ is 3 × 10^–3mollitre^–1 min^–1. What is the value of $\frac{- d\lbrack B\rbrack}{dt}$ in mollitre^–1 min^–1‑?

• A. 3 × 10^–3
• B. 9 × 10^–3
• C. 10^–3
• D. 1.5 × 10^–3

Answer 1

Answer: (B)

9 × 10^–3

Answer 2

$\frac{- d\lbrack A\rbrack}{dt}$ = – $\frac { 1 } { 3 }$ $\frac{d\lbrack B\rbrack}{dt}$

\ $\frac{- d\lbrack B\rbrack}{dt}$ = 3$\left\{ \frac{- d\lbrack A\rbrack}{dt} \right\}$ = 3 × 3 × 10^–3

= 9 × 10^–3 mol litre^–1 min^–1‑