Answer to Question #66358 in Physical Chemistry for tianna

Question

2. The thermal decomposition of ammonium nitrite (NH4NO2) into molecular nitrogen and water is a first-order process. NH4NO2(g) = 2H2O(g) + N2(g), at 680° C the rate constant for this reaction is 0.0198 s-1. How long will it take for an initial concentration of 0.57 M to fall to 0.013 M?

Answer 1

NH4NO2(g) = 2H2O(g) + N2(g)
Kr = 0.0198 s-1;
C0 = 0.57 M;
C = 0.013 M;
t - ?;
K_r=1/t∙ln C_0/C;
t=(ln C_0/C)/K_r ;
t=3.78/0.0198=191 s=3 min⁡11 sec
Answer: t = 3 min 11 sec.