Question

The rate law for the reaction 2A + B →C is –rA= kACA2CBwithkA= 25 (L/mol)2sec. What arekBandkC?

Answer 1

Explanation:

The given reaction equation is as follows.

             $2A + B \rightarrow C$

So, rate constants for different reactants and products written as follows.

             $\frac{-k_{A}}{\text{stoichiometric coefficient of A}} = \frac{-k_{B}}{\text{stoichiometric coefficient of B}} = \frac{k_{C}}{\text{stoichiometric coefficient of C}}$

As per the reaction equation, the stoichiometric coefficients of reactants and products are as follows.

         A = -2

         B = -1

         C = 1

Therefore,

      $\frac{-k_{A}}{\text{stoichiometric coefficient of A}} = \frac{-k_{B}}{\text{stoichiometric coefficient of B}} = \frac{k_{C}}{\text{stoichiometric coefficient of C}}$

      $\frac{-k_{A}}{-2} = \frac{-k_{B}}{-1} = \frac{k_{C}}{1}$    

             $\frac{-k_{A}}{-2} = k_{B} = k_{C}$

Hence,          $k_{B} = k_{C}$ = $\frac{25}{2} (L/mol)^{2}$

                                          = 12.5 $(L/mol)^{2}$

Thus, we can conclude that $k_{B}$ and $k_{C}$ are 12.5 $(L/mol)^{2}$.