Question

The differential rate law equation for the elementary reaction A + 2B $\overset{\quad K\quad}{\rightarrow}$3C, is :

• A. $- \frac{d\lbrack A\rbrack}{dt} = - \frac{d\lbrack B\rbrack}{dt} = \frac{d\lbrack C\rbrack}{dt}$= k [A] [B]2
• B. $- \frac{d\lbrack A\rbrack}{dt} = - \frac{1}{2}\frac{d\lbrack B\rbrack}{dt} = \frac{1}{3}\frac{d\lbrack C\rbrack}{dt}$= k [A]2 [B]
• C. $- \frac{d\lbrack A\rbrack}{dt} = - \frac{1}{2}\frac{d\lbrack B\rbrack}{dt} = \frac{1}{3}\frac{d\lbrack C\rbrack}{dt}$ = k [A] [B]2
• D. None of these

Answer 1

Answer: (C)

$- \frac{d\lbrack A\rbrack}{dt} = - \frac{1}{2}\frac{d\lbrack B\rbrack}{dt} = \frac{1}{3}\frac{d\lbrack C\rbrack}{dt}$ = k $A$ $B$2

Answer 2

A + 2B $\overset{\quad K\quad}{\rightarrow}$ 3C [elementary reaction]

Rate = – $\frac{d\lbrack A\rbrack}{dt} = - \frac{1}{2}\frac{d\lbrack B\rbrack}{dt} = \frac{1}{3}\frac{d\lbrack C\rbrack}{dt}$= k (1) (2)2