Answer to Question #139101 in General Chemistry for chacha

Question

Assuming that the chemical reaction obeys zero-order reaction, what is the time when of 14 M of substance A will decrease to 2 M, and the chemical reaction has k = 4.52x10 2 M/s?

3A → 2 B + C
(zero-order kinetics)

Answer 1

Given C_A0 = 14 M = initial concentration of the reactant at time t=0

C_A = 2M= final Concentration of the reactant at the time t

Rate constant K = 4.52×10²M/S

Time=t=?

Chemical reaction obeys zero order reaction

i.e n=0 (zero order kinetics)

Order of reaction with respect to A is zero i.e n= 0

3A------->2B + C

Rate equation

-r_A = KC_Aⁿ

Put n=0

-dC_A/dt = KC_A⁰

-dC_A/dt = K

So the Integrated form of above equation is

C_A0 - C_{A =} Kt

t = (C_Ao - C_A)/K

t =(14M - 2M)/(4.52×10²M/S)

t= 0.0265 sec