Rama tested the solubility of four substances at different temperatures and found in grams of each substance dissolved in 100 g of water to form a saturated solution.
`{:(,"Substance dissolved",,"Temperature (K)",),(,"(in grams)","293 K","313 K","333 K"),(1.,"Ammonium chloride","37 g","41 g","55 g"),(2.,"Potassium chloride","35 g","40 g","46 g"),(3.,"Sodium chloride","36 g","36 g","37 g"),(4.,"Potassium nitrate","32 g","62 g","106 g"):}`
(i) Which substance is least soluble at 293 K.
(ii) Which substance shows maximum change in its solubility when the temperture is raised from 293 K to 313 K ?
(iii) Find the amount of ammonium chloride that will separate out when 55 g of its solution at 333 K is cooled to 293 K.
(iv) What is the effect of temperature on the solubility of a salt ?
(v) What mass of sodium chloride would be needed to make a saturated solution in 10 g of water at 293 K ?

Explanation

(i) Potassium nitrate is least soluble in water at 293 K.
(ii) Potassium nitrate shows maximum change in its solubility which is 30 g (62-32) per 100 g of water.
(iii) From the available information, 55 g of ammonium chloride solution upon cooling from 333 K to 293 K separates salt = (55 - 37) = 18 g.
(iv) From the available information, it is clear that the solubility of salt in water increases with the rise in temperature
At 293 K, in a saturated solution,
100 g of water has sodium chloride = 36 g
10 g of water has sodium chloride = 3.6 g