Sodium sulphate is represented by the formula Na₂SO₄. In the criss-cross method, we consider the charges of the sodium ion (Na⁺) and the sulfate ion (SO₄²⁻). Since sodium has a charge of +1 and sulfate has a charge of -2, we need two sodium ions to balance the charge of one sulfate ion. This gives us the final formula Na₂SO₄.

Sodium sulfate, with the chemical formula Na₂SO₄, is formed through a process that involves balancing the charges of its constituent ions. Let's break this down:

Understanding the Ions

In sodium sulfate, we have two types of ions:

• Sodium Ion (Na⁺): This ion has a charge of +1.
• Sulfate Ion (SO₄²⁻): This ion carries a charge of -2.

Balancing the Charges

To create a neutral compound, the total positive charge must equal the total negative charge. Since the sulfate ion has a charge of -2, we need two sodium ions, each with a +1 charge, to balance it out:

• 2 (from Na⁺) = +2
• 1 (from SO₄²⁻) = -2

Final Formula

By combining two sodium ions with one sulfate ion, we arrive at the formula Na₂SO₄. This illustrates how the criss-cross method effectively helps in determining the correct ratio of ions in ionic compounds.