The rate expression for the reaction, `A_((g)) +B_((g)) rarr C_((g))`, is rate = `k[A]^2[B]^(1//2)`.
What changes in the initial concentrations of A and B will cause the rate of reaction to increase by a factor of eight?

Options

A. `[A]xx2,[B]xx2`
B. `[A]xx2,[B]xx4`
C. `[A]xx1,[B]xx4`
D. `[A]xx4,[B]xx1`

Answer

B

Explanation

If [A.]=2[A],[B.]=4[B]
Rate= `k[A.]^2[B.]^(1//2)=k[2A]^2[4B]^(1//2)=k[A]^2[B]^(1//2)xx8`