Answer
$CN^-$ is a Lewis base.
Work Step by Step
- Draw the Lewis structure.
1. Count the total electrons: C: 4; N: 5, Negative charge: 1; Total = 10 electrons.
2. Draw a C and a N, and make a bond between them.(-2 electrons = 8)
3. C is the central atom, so complete the nitrogen: (-6 electrons = 2)
4. Use the last electrons to fill the carbon (-2 electrons = 0)
5. Try to stabilize things, by using 2 lone pairs from the $N$ to make 2 more bonds with the carbon.
- Now, we know that, the carbon has 3 bonds and a lone pair, so, it is capable of donating this pair of electrons, making it a Lewis base.
