Question

Which of the following chemical formula is correct?

• A. $KCl$
• B. $K{Cl}_4$
• C. $Na{Cl}_2$
• D. $Na{Cl}_3$

Answer 1

The correct option is A $KCl$

An ionic compound is always electrically neutral, i.e., the cationic and anionic charge should balance out each other. The table below shows the chemical formulae given above along with their net charge.

$$\begin{array}{cccc}\text{Chemical formula}& \text{Total cationic charge}& \text{Total anionic charge}& \text{Net charge}\\ NaC{l}_2& \text{+1}& \text{-2}& \text{-1}\\ KCl& \text{+1}& \text{-1}& \text{0}\\ NaC{l}_3& \text{+1}& \text{-3}& \text{-2}\\ KC{l}_4& \text{+1}& \text{-4}& \text{-3}\end{array}$$
Thus, the only correct chemical formula (which is electrically neutral) is KCl.