Question

Consider the following reaction,

On increasing in temperature, which of the following product is predominant?

• A. E1 product is predominant
• B. $S_{N}1$ product is predominant
• C. No effect of temperature
• D. Both $E1$ and $S_{N}1$ forms equal amount

Answer 1

The correct option is A E1 product is predominant

In general, elimination reactions require higher temperature than substitution reaction.
If the temperature increases, then, rate of both substitution and elimination increases.
But, rate of elimination increases more than substitution. Hence, E1 product is preferred on increasing in temperature.


Reaction (II) leads to greater increase in entropy $(△n=1)$. Hence, favoured at higher temperature due to greater decrease in $△G$ than for reaction (I).