CHEMISTRY

JAMB 2004 - Question 19

Chemistry 2004 JAMB Past Questions - Question 19: Calcium tetraoxosulphate (VI) dissolves in water only sparingly to form a

Choose the correct answers from the options given.
Calcium tetraoxosulphate (VI) dissolves in water only sparingly to form a
A:
B:
C:
D:
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Correct Answer

D

Explanation

Calcium tetraoxosulphate (VI) is more commonly known as calcium sulfate or gypsum. When calcium sulfate dissolves in water, it undergoes a sparingly soluble reaction, forming calcium ions (Ca²⁺) and sulfate ions (SO₄²⁻). The balanced chemical equation for the dissolution of calcium sulfate in water is:

\[ \text{CaSO}_4 \, (s) \rightleftharpoons \text{Ca}^{2+} \, (aq) + \text{SO}_4^{2-} \, (aq) \]

The double arrow indicates that the reaction is in equilibrium, and calcium sulfate is sparingly soluble in water, meaning only a small amount of it dissolves. This is why it is often described as "sparingly soluble" or "insoluble" in water.

The solubility of calcium sulfate can be influenced by factors such as temperature. For example, its solubility generally increases with higher temperatures.