The solvolysis of t-butyl bromide in methanol yields 2-methylpropene in an E1 reaction (among other products). What is the effect on the rate of reaction of tripling the concentration of t-butyl bromide and doubling the concentration of methanol

See explanation

Explanation:

For a reaction that proceeds by E1 mechanism, the rate determining step involves the formation of the carbocation.  

The rate of formation of this carbocation depends only on the concentration of the t-butyl bromide since it is the only specie that enters into the rate equation.

Hence, when the concentration of t-butyl bromide is tripled, the rate of reaction is tripled.

Methanol does not enter into the rate equation hence doubling its concentration does not affect the rate of reaction.