Question

Calculate the order of reaction, $A \rightarrow$ 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,
$rate = 10.0 x 10^{-5} = k [0.003]^n$
...(i) (where, n is order of reaction)
from $2 ^{nd}$ reading
$rate 5.0 \times 10^{-5} =k [0.006] ^n$
Dividing eqn. (i) by (ii),
$\frac{10.0\times10^{-5}}{5.0\times10^{-5}}=\frac{k\left[0.003\right]^{n}}{k\left[0.006\right]^{n}}$
$2=\left(\frac{1}{2}\right)^{n} \Rightarrow n=-1$