JEE Main levelSingle correct optionDifficulty 2 of 3eq132
25.0 mL of saturated lime water (Ca(OH)X2) needs 18.0 mL of 0.0500 M HCl for neutralisation. Using molar mass 74 g/mol, the solubility of Ca(OH)X2 in g/L is:
A2.66g/L
B1.33g/L
C0.67g/L
D0.0180g/L
Answer: B
HCl = 0.0500 × 18.0 = 0.900 mmol HX+, and each Ca(OH)X2 gives 2 OHX−, so Ca(OH)X2 = 0.450 mmol in 25.0 mL, i.e. 0.0180 M. Solubility = 0.0180 × 74 = 1.33 g/L.