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)
(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: Option 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