Which of the following reactions can be used to synthesize nitriles?

In the SN2 reaction mechanism for nitrile formation, what is the role of the cyanide ion?

How does the formation of cyanohydrins from ketones potentially lead to the creation of chiral centers?

What intermediate is typically formed during the conversion of nitriles to ketones using Grignard reagents?

What are the products of acidic and basic hydrolysis of nitriles?