Question

What is the valency of Phosphate ions in ${\mathrm{AlPO}}_4$?

Answer 1

Valency:

• Valency can be defined as the combining capacity of an element or ion.

Valency of Phosphate ions in ${\mathrm{AlPO}}_4$:

Step 1: Determine the charge or valency of $\mathrm{Al}$

• Since $\mathrm{Al}$ is a trivalent cation, it has $+3$ charge.
• Suppose, Phosphate ion has valency or charge $x$.
• The total charge on the compound is zero as it is a neutral compound.

Step 2: Add charges of both ions and equate to zero

$$\begin{gathered} 3+x=0 \\ x=-3 \end{gathered}$$

Hence, the valency of Phosphate ions is $-3$.