Question #6d3a4

1 Answer
Jul 11, 2017

Answer:

Here's what I got.

Explanation:

You can't really talk about sigma and pi bonds for calcium cyanamide, #"CaCN"_2#, because this compound is actually ionic.

A formula unit of calcium cyanamide contains a calcium cation, #"Ca"^(2+)#, and a cyanamide anion, #"CN"_2^(2-)#.

https://en.wikipedia.org/wiki/Calcium_cyanamide

So my guess would be that you're actually interested in figuring out the number of sigma and pi bonds present in the cyanamide anion.

Now, you should know that you have

  • #"1 single bond = 1"# #sigma# #"bond"#
  • #"1 double bond = 1"# #sigma + 1 pi# #"bond"#
  • #"1 triple bond = 1"# #sigma + 2 pi# #"bonds"#

According to the Lewis structure of the cyanamide anion, which you can see on the right of the image, the central carbon atom is bonded to two nitrogen atoms via double bonds.

This means that the cyanamide anion will have a total of

  • #2# #sigma# #"bonds " -># one form each of the two double bonds
  • #2# #pi# #"bonds " -># one from each of the two double bonds