The solubility of sodium nitrate is 114 g at 50 degrees Celsius and 96 g at 30 degrees Celsius (per 100 g water). How much salt is thrown out when a saturated solution containing 50 g of water is cooled from 50 to 30 degrees Celsius?

1. Salt dissolved in 50 g water at 50 degrees Celsius = (114 x 50) / 100 = 57 g. 2. Salt dissolved in 50 g water at 30 degrees Celsius = (96 x 50) / 100 = 48 g. 3. On cooling, the excess salt crystallises out: 57 - 48 = 9 g. 4. So 9 g is thrown out; 57 g and 48 g are the dissolved amounts before subtracting, not the crystallised mass. _Source: Samacheer Kalvi (TN SCERT) Class 10 Science, Unit 9 Solutions "Problems Based on Solubility", p.138_