9.43. Choose the incorrect statement:

(a) Hard water is not suitable for laundry.

(b) Temporary hardness can be removed by boiling.

(c) Calgon is used for removing permanent hardness of water.

(d) Calgon forms precipitates with Ca²⁺ and Mg²⁺.

H₂S has minimum boiling point.

PbS + 4H₂O_2->PbSO₄ + 4H₂O.

Volume strength of H₂O₂ = Molarity * 11.2

HF molecules are associated with strong intermolecular hydrogen bonding hence its boiling point is the highest

Compound             Melting Point (K)

HF                          190

HCl