Question

For a zero order chemical reaction,
$2N{H}_3\left(g\right)\to N_2\left(g\right)+3H_2\left(g\right)$
rate of reaction = 0.1 atm / sec. Initially only $N{H}_3$ is present & its pressure = 3 atm. Calculate total pressure(in atm) at t = 10 sec.

Answer 1

Given,
$2N{H}_3\left(g\right)\to N_2\left(g\right)+3H_2\left(g\right)$
Pressure at t=0 3 0 0
Pressure at t=10 (3-2x) x 3x

Rate of Reaction = $-\frac{1}{2}$$\frac{d\left(N{H}_3\right)}{dt}$ = 0.1
$\Rightarrow \frac{-d\left(N{H}_3\right)}{dt}=0.2$
For zero order, $C_A=C_{A_0}–Kt$
or (3–2x) = 3 – 0.2 × 10
or x = 1
$\Rightarrow P_{total}$ = (3 – 2x) + x + 3x = 3 + 2x = 5 atm