Consider the reaction 

CH₃CH₂CH₂Br + NaCN $\to$CH₃CH₂CH₂CN + NaBr

This reaction will be the fastest in

1. ethanol

2. methanol

3. N,N'-dimethylformamide (DMF)

4. water

Consider the reaction,

This reaction will be the fastest in:

1. Ethanol

2. Methanol

3. N, N'-dimethylformamide (DMF)

4. Water

A few reactions are given below:

i.	\(\small{\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{CH}_2 \mathrm{Br}+\mathrm{KOH} \rightarrow \mathrm{CH}_3 \mathrm{CH}=\mathrm{CH}_2+\mathrm{KBr}+\mathrm{H}_2 \mathrm{O}}\)
ii.
iii.