Question

For a chemical reaction rate law is, rate $= k[A]^{2}[B]$ If $[A]$ is doubled at constant $[B]$, the rate of reaction

• A. increases by a factor of $8$
• B. increases by a factor of $4$
• C. increases by a factor of $3$
• D. increases by a factor of $2$

Answer 1

Answer: (B)

increases by a factor of $4$

Answer 2

Given,

Initial rate $=k[A]^{2}[B]$

If $[A]^{1}=2[A]$

Rate $k=[2 A]^{2}[B]=4 k[A]^{2}[B]$

Thus, if the concentration of $A,[A]$ is doubled and that of $[B]$ is constant, then initial rate increases by a factor of 4