Question

What is the effect of shaking dilute sulphuric acid with a small quantity of colourless anhydrous copper sulphate?

• A. The solid dissolves to give a colourless solution
• B. The solid dissolves to give a blue soluton
• C. The solid turns blue but does not dissolve
• D. The solid dissolves to give a red solution

Answer 1

Answer: (B)

The solid dissolves to give a blue soluton

Copper(II) oxide, a black solid, and colourless dilute sulphuric acid react to produce copper (II) sulphate, giving a characteristic blue colour to the solution. From this solution, blue copper(II) sulfate pentahydrate crystals may be obtained if desired.