How does temperature affect SN1 reactions?

Question

Ella Allen · Accepted Answer

A rise in temperature should accelerate a bond-breaking reaction......

Of course, temperature increase generally increases the rate of most chemical reactions, however, for a typical #S_N1# reaction, we may invoke the following elemental step: #RCH(X)R'rightleftharpoonsRC^+HR' +X^-# This represents the reaction's rate-determining step. And because this, the rate determining step, involves BOND-BREAKING, we would predict that an increase in temperature should result in the production of more #RC^+HR# species, and thus an INCREASE in the rate of reaction.......... Another way to look at this is to include heat, i.e. #Delta#, as a virtual reactant............. #RCH(X)R' +DeltarightleftharpoonsRC^+HR' +X^-# If we raise the temperature, we supply #Delta#, and, therefore, we should drive the equilibrium to the RIGHT as shown.

Ella Allen · Answer

undefined Temperature influences SN1 reactions by affecting the rate of reaction. Higher temperatures increase molecular kinetic energy, leading to more frequent and energetic collisions between reactant molecules. This accelerates the rate of ionization in SN1 reactions, promoting the formation of the carbocation intermediate.