Question

The catalytic decomposition of $N_{2}O\left(g\right)$ by gold at ${900}^o$C and at an initial pressure of $200$mm is $50\%$ completed in $53$ minutes and $73\%$ completed in $100$ minutes.
(i) What is the order of the reaction?
(ii) Calculate the velocity constant.
(iii) How much of $N_{2}O\left(g\right)$ will decompose in $100$min, at the same temperature but at initial pressure of $600mm$?

Answer 1

$50\%$ completetd in approx 50 min,

to get the order-

$Kt=2.303\log \frac{A_o}{A_o-x}$

$K=\frac{2.303}{50}\log \frac{100}{50}$

$k=.013mi{n}^{-}1$

(i)hence the value of k is constant so order of reaction is $1$.

(ii)Velocity constant = $.013mi{n}^{-1}$

(iii)As the first order reaction does not depend upon the intial conc. so it will decompose same.