Chemistry - Chemical Kinetics Question with Solution | TestHub

The reaction is zero order.

$$-\frac{1}{4}\frac{\mathrm{d}[\mathrm{A}]}{\mathrm{dt}}={\mathrm{K}}_{reaction}$$

So,

$$-\frac{\mathrm{d}[\mathrm{A}]}{\mathrm{dt}}=4\times \mathrm{K}=20mm/sec$$

Now, at time $t$,

$$[\mathrm{A}]=[\mathrm{A}{]}_0-\mathrm{K}\times \mathrm{t}$$

For ${\mathrm{p}}_{\mathrm{A}}$,

$${\mathrm{p}}_{\mathrm{A}}=4000-20\times 100$$

$${\mathrm{p}}_{\mathrm{A}}=2000\mathrm{mm}\mathrm{of}\mathrm{Hg}$$

Now, ${\mathrm{p}}_{\mathrm{B}}=\frac{3}{4}\times 500=1500.00$.

Now, ${\mathrm{T}}_{final}$ when ${\mathrm{P}}_{\mathrm{A}}=0$, so

$$\mathrm{t}=200\sec$$

So, after $250\sec$,

$${\mathrm{P}}_{\mathrm{T}}=\frac{3}{4}\times 4000+\frac{2}{4}\times 4000$$

$$=3000+2000=5000$$