Question

Why does C-N have a greater electron density than C-Cl?

Answer 1

Nitrogen is an electron donating group, as it has +ve resonance effect (mesomeric).

Explanation:

Nitrogen is an electron donating group (due to having unshared electrons termed as lone pairs.), so having +ve resonance effect (mesomeric). But be aware that if Nitrogen has a positive charge on it (quaternary nitrogen), it will pull electrons towards it, as it becomes an electron withdrawing group.

Chlorine has high electronegativity, so pulling electrons from carbon atom (i.e electrons stay longer at the Cl that C.) through -ve inductive effect.