Identify A and B in each of the following processes :
(i) `CH_(3)CH_(2) overset(NaCN) to A underset(Ni//H_(2)) overset("reduction") to B`
(ii) ` C_(6)H_(5)NH_(2)overset(NaNO_(2))toAunderset(OH^(-))overset(C_(6)H_(5)NH_(2)) to B`

Explanation

To solve the problem, we need to identify the compounds A and B in the given chemical processes. Let's break down each process step by step.

### Process (i):
1. **Starting Compound**: The starting compound is ethane, represented as \( CH_3CH_2 \).
2. **Reagent**: The first reagent is sodium cyanide (\( NaCN \)).
3. **Reaction Type**: The reaction of ethane with \( NaCN \) leads to the formation of a nitrile. The product A is thus **propionitrile** or **propane nitrile**, represented as \( CH_3CH_2CN \).
4. **Next Step**: The next step involves the reduction of A using hydrogen gas (\( H_2 \)) in the presence of a nickel catalyst (\( Ni \)).
5. **Reduction Outcome**: The reduction of propionitrile will convert the nitrile group (\( -CN \)) into an amine group (\( -NH_2 \)). Therefore, product B is **propylamine**, represented as \( CH_3CH_2CH_2NH_2 \) or **propane-1-amine**.
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