Question

Calculate the order of reaction, $A\to$ Product, from the following data

[A] moles/ L	d [product] /dt (moles/L/sec)
0.03	$10.0\times 10^{-5}$
0.006	$5.0\times 10^{-5}$
0.012	$2.5\times 10^{-5}$

• A. 1
• B. -2
• C. -1
• D. 2

Answer 1

Answer: (C)

From $1^{st}$ reading,
$rate=10.0x10^{-5}=k[0.003{]}^n$
...(i) (where, n is order of reaction)
from $2^{nd}$ reading
$rate5.0\times 10^{-5}=k[0.006{]}^n$
Dividing eqn. (i) by (ii),
$\frac{10.0\times 10^{-5}}{5.0\times 10^{-5}}=\frac{k{\left[0.003\right]}^n}{k{\left[0.006\right]}^n}$
$2={\left(\frac{1}{2}\right)}^n\Rightarrow n=-1$