Rate law for the reaction, `A + 2B to C` is found to be
Rate `= k [A] [B]`
Concentration of reactant 'B' is doubled keeping the concentration of 'A' constant, the value of rate constant will be _______

Options

A. the same
B. doubled
C. quadrupled
D. halved

Answer

B

Explanation

Rate law can be written as
Rate = K [A] [B]
Rate of reaction w.r.t B is of first order.
`" "R_(1) = k [A][B]`
when concentration of reactant 'B' is doubled then rate `(R_(2))`
`" "R_(2) = k[A][B]`
`" R_(2) = 2k [A][B]`
`" "R_(2) = 2R_(1)`
Therefore, as concentration of B is doubled keeping the concentration of A constant rate of reaction doubles.