5cm3 of a saturated solution of sodium chloride at 30°C gave, on careful evaporation, 1.95g of solid salt. The solubility of sodium chloride at 30°C? (Na = 23, Cl = 35.5)
A. 5.00 mole dm3 B. 5.67 mole dm3 C. 6.00 mole dm3 D. 6.67 mole dm3 E. 7.00 mole dm3
Correct Answer: D
Explanation
1.95 gms of NaCl dissolves in 5 cm solution at 30°C Number of gm of solute required to dissolve in 100 gm = (1.950 x 100)/ (5 x 1) = 1.95 x 20 = 39.0 390 gms will dissolve in 1000 dm3 Solution Solubility of NaCl at 30°C in (dm3 is 390)/(Mol wt g NaCl) = 6.67 mol dm3
