Question

The following data were obtained at a certain temperature for the decomposition of Ammonia in contact with a tungsten

P (mm)	50	100	200
$t_{1/2}$	3.64	1.82	0.90

The order of the reaction is:

• A. 1
• B. 2
• C. 3
• D. 0

Answer 1

Answer: (B)

2

For a reaction of order n,
${\frac{a_2}{a_1}}^{n-1}=\frac{t_1}{t_2}$
For first and second experiment,
${\frac{100}{50}}^{n-1}=\frac{3.64}{1.82}$
${\frac{2}{1}}^{n-1}=\frac{2}{1}$
$n-1=1$
$n=2.$