Analytical chemistry | cupric ion | cu2+ ions using NaOH | Identification of cations

When sodium hydroxide (NaOH) is added to a solution containing copper sulfate (CuSO4), a blue precipitate of copper(II) hydroxide (Cu(OH)2) forms. The chemical reaction can be represented as follows:

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

In this reaction, copper sulfate (CuSO4) reacts with sodium hydroxide (NaOH) to produce copper(II) hydroxide (Cu(OH)2), which is a pale blue precipitate. Sodium sulfate (Na2SO4) remains in the solution.

Again, the formation of a pale blue precipitate indicates the presence of copper ions (Cu2+) in the original solution. This reaction is a common qualitative test used to identify the presence of copper ions in a sample.