JEE PYQ: Chemical Kinetics Question 35
Question 35 - 2019 (09 Jan Shift 2)
For the reaction, $2\text{A} + \text{B} \to$ products, when the concentrations of A and B both were doubled, the rate of the reaction increased from 0.3 mol $\text{L}^{-1}\text{s}^{-1}$ to 2.4 mol $\text{L}^{-1}\text{s}^{-1}$. When the concentration of A alone is doubled, the rate increased from 0.3 mol $\text{L}^{-1}\text{s}^{-1}$ to 0.6 mol $\text{L}^{-1}\text{s}^{-1}$. Which one of the following statements is correct?
(1) Total order of the reaction is 4
(2) Order of the reaction with respect to B is 2
(3) Order of the reaction with respect to B is 1
(4) Order of the reaction with respect to A is 2
Show Answer
Answer: (2)
Solution
$r = K[\text{A}]^x[\text{B}]^y$. $\frac{r_2}{r_1} = 2^x \cdot 2^y = \frac{2.4}{0.3} = 8$, so $x + y = 3$. $\frac{r_3}{r_1} = 2^x = \frac{0.6}{0.3} = 2$, so $x = 1$. Therefore $y = 2$.
BETA
