When copper sulfate (CuSO₄) and sodium hydroxide (NaOH) are mixed in an aqueous solution, they undergo a double displacement reaction to form copper hydroxide (Cu(OH)₂) and sodium sulfate (Na₂SO₄).

Here's the balanced chemical equation:

CuSO₄(aq) + 2NaOH(aq) → Cu(OH)₂(s) + Na₂SO₄(aq)

Here's what happens:

1. Formation of Copper Hydroxide: Copper sulfate (CuSO₄) is a blue crystalline solid that dissolves in water to form copper(II) ions (Cu²⁺) and sulfate ions (SO₄^2-). Sodium hydroxide (NaOH) is a white solid that dissolves in water to form sodium ions (Na⁺) and hydroxide ions (OH^-). When the solutions are mixed, the copper(II) ions react with the hydroxide ions to form copper hydroxide (Cu(OH)₂), which is a pale blue precipitate that is insoluble in water.

2. Formation of Sodium Sulfate: The sodium ions (Na⁺) from the sodium hydroxide react with the sulfate ions (SO₄^2-) from the copper sulfate to form sodium sulfate (Na₂SO₄). Sodium sulfate is soluble in water and remains dissolved in the solution.

Observations:

* You will observe a pale blue precipitate forming in the solution.

* The solution will change color from blue to a lighter shade of blue or even slightly green.

* The reaction is exothermic, meaning it releases heat.

Important Note: Copper hydroxide is slightly soluble in water, so some of it may dissolve. This will make the precipitate appear less dense.