The chemical equation for this reaction is:

CuSO4 + 2NaOH → Cu(OH)2 + Na2SO4

Explanation:

1. Formation of Copper Hydroxide:

When copper sulphate, a blue crystalline compound, is mixed with sodium hydroxide, a strong base, the copper ions (Cu2+) in the copper sulphate react with the hydroxide ions (OH-) from sodium hydroxide. This reaction leads to the formation of copper hydroxide, which is a light blue gelatinous precipitate.

2. Formation of Sodium Sulphate:

As copper hydroxide is formed, the sulphate ions (SO42-) from copper sulphate combine with the sodium ions (Na+) from sodium hydroxide to form sodium sulphate. Sodium sulphate is a white, water-soluble compound that remains in the solution.

3. Color Change:

The addition of sodium hydroxide to copper sulphate solution results in a noticeable change in color. The initial blue color of the copper sulphate solution turns into a light blue or greenish-blue color due to the formation of copper hydroxide.

4. Precipitation:

As the reaction proceeds, copper hydroxide precipitates out of the solution and forms a solid, gelatinous layer at the bottom of the container. This is because copper hydroxide is insoluble in water.

Overall, the reaction between copper sulphate and sodium hydroxide produces copper hydroxide precipitate and sodium sulphate in the solution. The color change and the formation of the precipitate indicate the occurrence of the chemical reaction.