![If in the graph above 1 dm 3 of a saturated solution of KCL is cooled from 80°C, the mass of crystals deposited will be
[K = 39, Cl = 35.5]](/img/aptitude-tests/questions/33267.jpeg "If in the graph above 1 dm 3 of a saturated solution of KCL is cooled from 80°C, the mass of crystals deposited will be
[K = 39, Cl = 35.5]")
If in the graph above 1 dm 3 of a saturated solution of KCL is cooled from 80°C, the mass of crystals deposited will be [K = 39, Cl = 35.5]
A.
7.45 g
B.
14.90 g
C.
74.50 g
D.
149.00 g
Correct answer is D
Trace the graph to the y-axis to obtain the solubility of the salt at 80°C and at the point where the straight line touches the y-axis, the solubility of the salt at these respective temperatures is 4mol\dm3 and 6mol\dm3 solubility of salt that will crystallize out = 6- 4 = 2mol\dm3 therefore mass of salt deposited = solubility x molar mass of salt 2 x 74.5 = 149.00g