Question

Alum powder does not dissolve in water (True or False)

Answer 1

Hint: Alum powder is a colourless and odourless crystalline powder. Alum is a chemical that is used for speeding up sedimentation and this process is known as loading because as soon as alum is added to the water it makes the suspended impurities heavier resulting in the quick settlement of the impurities. The most important alums are potassium alum, sodium alum and ammonium alum.

Complete answer:
Alum powder when dissolved in hot water gets dissolved. Thereby, proving that alum powder is soluble in hot or warm water. Moreover, the solubility of alum in water depends greatly on its chemical composition also as sodium is highly soluble in water hence sodium alum is also readily soluble in water but caesium alum and rubidium alum are sparingly or slightly soluble in water. Also, the solubility of alum powder in water is directly proportional to the temperature of the water which means that as the temperature of the water increases the solubility of alum powder in water also increases and vice –– versa.
Alum forms a true solution when it is dissolved in water which is pale yellow in colour, which again proves that alum is soluble in water.
Therefore, it is false that alum powder does not dissolve in water.

Note:
True solution can be prepared by adding a pinch of alum powder in distilled water. Potassium alum is one of the common forms of alum which is widely used as a flocculant for clarifying turbid liquid. Aluminium bases alum have industrial importance and are used in many industrial processes.