Question

The experimental data for the reaction,$2A + B_2 \to 2AB,$ is

Expt. No	$\left[A\right]$	$\left[B_{2}\right]$	$Rate\left(s^{-1}\right)$
1.	$0.50$	$0.50$	$1.6 \times 10^{-4}$
2.	$0.50$	$1.00$	$3.2 \times 10^{-4}$
3.	$1.0$	$1.00$	$3.2 \times 10^{-4}$

The rate equation for the above data is -

• A. $rate=k\left[B_{2}\right]^{2}$
• B. $rate=k\left[B\right]$
• C. $rate=k\left[A\right]^{2}\left[B\right]^{2}$
• D. $rate=k\left[A\right]^{2}\left[B\right]$

Answer 1

Answer: (B)

$r=k\left[A\right]^{x}\left[B\right]^{y}$
$1.6\times10^{-4}=k\left[0.5\right]^{x}\left[0.5\right]^{y} .....\left(1\right)$
$3.2\times10^{-4}=k\left[0.5\right]^{x}\left[1.0\right]^{y} .....\left(2\right)$
$3.2\times10^{-4}=k\left[1.0\right]^{x}\left[1.0\right]^{y} .....\left(3\right)$
$\left(2\right)\div\left(1\right) 2=2y \Rightarrow y=1$
$\left(3\right)\div\left(2\right) 1=2x \Rightarrow x=0$
$r=k\left[A\right]^{\circ}\left[B\right]^{1}\Rightarrow r=K\left[B\right]$