Question

At high pressure the following reaction is zero order.
`" "2NH_(3)(g) underset("Platinum catalyst")overset(1130 K)to N_(2)(g) + 3H_(2)(g)`
Which of the following options are correct for this reaction ?
A. Rate of reaction = Rate constant
B. Rate of the reaction depends on concentration of ammonia
C. Rate of decomposition of ammonia will remin constant until ammonia disappears completely
D. Further increases in pressure will change the ratio of reaction

Answer 1

Correct Answer - A::C::D
Given, chemical reaction is
`" "2NH_(3)(g) underset("Platinum catalyst")overset(1130 K)to N_(2)(g) + 3H_(2)(g)`
At very high pressure reactions become independent of ammonia i.e., zero order reaction
Hence, `" ""Rate"= k[p_(NH_(3))]^(0)`
`" ""Rate" = K`
(a) Rate of reaction = Rate constant
(b) Rate of decomposition of ammonia will remain constant until ammonia disappears completly.
(c) Since, formation of ammonia is reversible process furhter increases in pressure will change the rate of reaction. According to Le-Chatelier principle increases will favour in backward reaction.