In the reaction A + B C, doubling the concentration of A doubles the reaction rate and doubling the concentration of B does not affect the reaction rate. What is the rate law for this reaction?

rate = k[B]

rate = k[A]2

rate = k[A][B]

rate = k[A]

Verified Answer :

The rate law for the reaction wherein you double the concentration of A doubles the reaction rate and doubling the concentration of B does not affect the reaction rate would be rate = k[A]2. This is because if 2 is multiplied by the concentration, the rate also doubles.

Answer: Option (d) is the correct answer.

Explanation:

Rate law is the rate which is in equilibrium with the concentration of reactants raised to the power of their coefficients.

For example,  \(xA + yB \rightarrow zC\)

           Rate, r = k \([A]^{x} \times [B]^{y}\)    ........ (1)

So, when concentration of A is doubled then rate of reaction also doubles. Hence, then rate law will be as follows.

                  2r = k \([2A]^{x} \times [B]^{y}\)     ......... (2)

Dividing equation (1) by (2) we get the following.

      \(\frac{r}{2r}\) = \(\frac{k[A]^{x} \times [B]^{y}}{k[2A]^{x} \times [B]^{y}}\)

Therefore, cancelling common factors we get the following.

               \(\frac{1}{2} = \frac{1}{2x}\)

                 \(2^{x}\) = 2

                             x = 1

Thus, we can conclude that in the reaction A + B C, doubling the concentration of A doubles the reaction rate and doubling the concentration of B does not affect the reaction rate then rate of reaction will be as follows.

                            rate = k[A]