Question

For the reaction a gives b the rate of reaction becomes 3 times when the concentration of a is increased by 9 yimes what is the order of reaction

Answer 1

the order of reaction is half order

Answer 2

Answer:Order =$\frac{1}{2}$

Explanation: Elementary reactions are reactions which takes place in single step. For elementary reactions the order is same as the stoichiometric coefficients.

Thus for the reaction:  

$a\rightarrow b$

Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.

$R=[a]^x$    (1)

On increasing the concentration of a by 9 times the rate becomes 3 times.

$3R=[9a]^x$     (2)

Dividing 2 by 1  

$\frac{3R}{R}=\frac{[9a]^x}{[a]^x}$

$3=\frac{[9]^x[a]^x}{[a]^x}$

$3={[9]^x}$

$3=3^{2x}$

$2x=1$

$x=\frac{1}{2}$

As the order with respect to a is $\frac{1}{2}$, on increasing the concentration of a by 9 times, the rate will become 3 times of the original rate.