Question

5. Two reactants combine to form a product in the reaction A + B -> C. The rate of the reaction depends on the concentrations of both
reactants squared (rate = k[A]2 [B]2). What's the total reaction order of this reaction?
A. 4
B. 1
C. 2.
O D.3​

Answer 1

Answer:

C. 2.

Explanation:

The total reaction order of this reaction is second order (2). For a second order reaction ,the rate  depends on two variable concentration terms which may or may not be same.

Given that:

Two reactants combine to form a product in the reaction  A + B → C

The above reaction is bimolecular as two molecules are involved in the reaction.

If $C_A$ and $C_B$ are the concentrations of A and B respectively at any time t, then assuming  that the reaction is of first order with respect to both A and B , the overall order is second and the reaction rate is given by:

$\mathbf{\dfrac{-dC_A}{dt}=\dfrac{-dC_B}{dt}=k_2C__AC_B}$

where;

$\mathbf{k_2}$ = specific rate constant for a second order reaction and becomes the rate of the reaction when both $C_A$ and $C_B$ are unity.