Question

A student tried to detect the presence of calcium Ion t(Ca²⁺) In milk by adding Na₂SO₄ solution to a sample of milk. Briefly comment on the likely results of her experiment.

Answer 1

The addition of sodium sulfate to milk to detect calcium ions is likely to result in a precipitate of calcium sulfate, as the ion product may exceed the Ksp, causing calcium sulfate to precipitate.

Step-by-step explanation:

When a student adds sodium sulfate (Na2SO4) to a sample of milk to detect the presence of calcium ions (Ca2+), the likely result is the formation of a precipitate of calcium sulfate (CaSO4).

This occurs because the ion product of calcium and sulfate ions in the solution may exceed the solubility product constant (Ksp) for calcium sulfate, leading to its precipitation.

In experiments, adding a compound like sodium sulfate that contains a common ion can result in a precipitate if the resultant mixture surpasses the Ksp value, according to Le Chatelier's Principle.

When the student adds Na2SO4 solution to the milk sample, a chemical reaction occurs between the calcium ions in the milk (Ca²⁺) and the sulfate ions in the Na2SO4 solution.

This reaction forms insoluble calcium sulfate (CaSO4), which precipitates out of the solution as a solid. The likely result of the experiment is the formation of a white precipitate of calcium sulfate in the milk sample.