Question

1. What is heavy water? Mention one use of heavy water. 

2. Explain why hydrogen peroxide is not stored in glass vessels. 

3. What is calgon? What is its use?

Answer 1

1. D₂O. Used as moderator in nuclear reactors. 

2. To prevent its decomposition. 

3. Calgon is chemically sodium hexametaphosphate (Na₆P₆O₁₈). It is used to remove Ca²⁺ and Mg²⁺ ions of hard water by converting them into soluble complexes. 

M²⁺ + Na₄P₆O^2-₁₈ → [Na₂MP₆O₁₈]^2- + 2Na⁺ (M = Mg,Ca)