Question

Assuming an elementary reaction h2o2 +3i+2h=2h2o+i3 the affect on the rate of the rection boight about by doubling the concentration of i without changing the order

Answer 1

Answer: Rate will increase 8 times.

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: $H_2O_2 +3I+2H\rightarrow 2H_2O+I_3$

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.

$R=k[H_2O_2]^1[I]^3[H]^2$     (1)

On doubling the concentration of I,

$R'=k[H_2O_2]^1[2I]^3[H]^2$    (2)

Dividing 2 by 1

$\frac{R'}{R}=8$ , R' = 8 R

As the order with respect to I is 3, on doubling the concentration of I, the rate will become 8 times of the original rate.