Question

If the valency of carbon is 4 and that of sulphur is 2, work out the formula of the compound formed by the combination of carbon with sulphur. What is the name of this compound ?

Answer 1

Valency of carbon = 4
Valency of sulphur = 2


$\begin{array}{ccc}\mathrm{Elements}:& \mathrm{C}& \mathrm{S}\\ \mathrm{Valencies}:& 4& 2\end{array}$

Formula for the compound containing carbon and sulphur can be worked out by crossing the valencies of the constituent elements.
Thus, formula of the compound (formed by the combination of carbon and sulphur) is C₂S₄. The formula has a common factor of 2; therefore, dividing the formula by the common factor gives us the simplest chemical formula, i.e., CS₂.
This compound is called carbon disulphide.