Question

CH3CHO + [NaCN + NH4Cl] gives what? And how?!? I seem to have forgotten the basics of reactions of organic chemistry :/

Answer 1

@gsoda help out?

Answer 2

it's late and i am tired, so i am just going to guess: remember that the aldehyde group is a target for nucleophiles. the sp2 carbon is somewhat electron-deficient because of the electronegativity difference and other reasons.

so my guess is: [CN]- attacks the aldehyde carbon, and the aldehyde oxygen becomes O-. this O- takes a proton from NH4^+, and becomes an OH. Na+ pairs up with Cl-.

Answer 3

You have a strong base and a weak acid. (I'm going to say the acid - \(NH_4Cl\) is used here as a wash to neutralize the product in the reaction\).

@gsoda is correct. \(CN^-\) here would be your nucleophile.
You can compare pKa to see where the reaction will lie to help you dictate reactions :)
pKa of \(CN^-\) = ~ ____
pKa of aldehyde (proton): = ~ ____
not 100% the values but you can find them in your book or online. Best of luck!

Answer 4

@abb0t makes sense, thanks!