Valency of Element X

Element X has a valency of 3, which means that it can form compounds by gaining or sharing three electrons with other elements. This indicates that element X has three valence electrons available for bonding.

Formula of Sulphate

The formula of a compound is determined by the valencies of the elements involved. In the case of the sulphate ion, it consists of a sulfur atom bonded to four oxygen atoms, with a charge of -2. Since the valency of element X is 3, it would require two sulfate ions to balance the charge.

Explanation

To form a stable compound, element X needs to lose three electrons to achieve a stable electron configuration. On the other hand, the sulfate ion (SO4^2-) has a charge of -2, which means it has gained two electrons to achieve stability.

To balance the charges, two sulfate ions (each with a charge of -2) are needed to combine with three element X ions (each with a charge of +3). This results in a compound with the formula X2(SO4)3.

In this compound, the valency of element X is represented by the subscript "2" outside the brackets. The brackets indicate that the sulfate ion is a polyatomic ion, consisting of multiple atoms. The subscript "3" inside the brackets indicates that there are three sulfate ions in the compound.

Summary

In summary, the formula of the sulphate compound involving an element X with a valency of 3 is X2(SO4)3. This formula is derived by balancing the charges of the element X and the sulfate ion. Element X, with a valency of 3, requires two sulfate ions (each with a charge of -2) to achieve stability. The resulting compound is visually represented as X2(SO4)3.