What's the product of these organic reactions?

[Janiceleong26]

1. Homework Statement

For part a), I know that it is a nucleophilic addition reaction of CN- to form cynohydrin, but how come there are 2N atoms in E? How does NH4+ react with CH3CHO or the cynohydrin formed?

For part b), what reaction is this?

Homework Equations

The Attempt at a Solution

 

[Janiceleong26]

I've figured out how to solve them already.