Question

A student was asked by her science teacher to prepare a true solution. She dissolved the solute in water but forgot to record its name. What may be the correct name of the solute ?
(1) barium sulphate
(2) sulphur powder
(3) alum
(4) egg albumin

Answer 1

The true solution is a homogeneous mixture of two or more compounds in which the size of the solute particle is less than 1nm.
Barium sulphate is insoluble in water, while egg albumin and sulphur powder form colloidal sols, but alum dissolves in water to give the true solution.

Hence, the correct answer is option 3.