The Reaction of Methyl Iodide with Sodium Azide, NaN₃, Proceeds

Multiple Choice

The reaction of methyl iodide with sodium azide, NaN₃, proceeds by an S_N2 mechanism. What is the effect of doubling the concentration of NaN₃ on the rate of the reaction?

A) the rate remains the same
B) the rate decreases by a factor of 2
C) the rate increases by a factor of 2
D) the rate increases by a factor of 4