Question

The total number of bonds in tetra cyano methane is __________

Answer 1

The total number of bonds in any compound is the sum of total sigma bonds and pi bonds. The molecular formula of tetra cyano methane is $C{(CN)_4}$.

Complete answer:
Tetra cyano methane is also known as carbon tetracyanide. It is a percyanoalkane with molecular formula $C{(CN)_4}$. The structure can be considered methane with all hydrogen atoms replaced by cyanide groups. Tetra cyano methane is a solid at room temperature. It decomposes over 160 °C without melting, and although it can be in a dilute vapor, no liquid form is known.
The molecules of tetra cyano methane have a tetrahedral geometry with a carbon atom at the center and four CN atoms surrounding it. The C - C bond length is 1.484 angstrom and the C ≡ N bond length is 1.161 angstrom in the gas form. In the solid, the C ≡ N bond shortens to 1.147 angstroms. At pressures over 7 GPa tetra cyano methane starts to polymerize to form a disorganized covalent network solid. At the higher pressure the color yellows and darkens to black.
The structure of tetra cyano methane is:

As clearly seen from the structure, there are four C-C sigma bonds and four C-N sigma bonds. So, there is a total of eight sigma bonds. And there are eight C-N pi bonds. So, there is a total of eight pi bonds. Hence, there is a total of 16 bonds in tetra cyano methane.
Therefore, the correct answer is 16.

Note: When asked about the total bonds of $C{(CN)_4}$, a student can forget to count the bonds between carbon and nitrogen. Then his incorrect answer would come out to be 4.