Question

For a reaction $A+B\to C$, the rate law is written as $r=k\left[A^2\right]\left[B\right]$. Doubling the concentration of $A$ without changing concentration of $B$ increases the rate of reaction by:

• A. $2$ times
• B. $4$ times
• C. $8$ times
• D. $16$ times

Answer 1

Answer: (B)

$4$ times

$A+B\to C$, the rate law is written as $r=k\left[A^2\right]\left[B\right]$.
Rate of reaction is proportional to $[A{]}^2$. Doubling the concentration of $A$ without changing concentration of $B$ increases the rate of reaction $r_1=k\left[2A{]}^2\right[B]=4r$
the rate will be increased by 4 times.