To make a saturated solution 36g of sodium chloride is dissolved in 100g of water at 293 k

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 ? (a) To make a saturated solution, 36 g of sodium chloride is dissolved in 100 g of water at 293 K. Find the concentration at this temperature. (b) What is the effect of temperature on the solubility of a solid in a liquid ? (c ) Why is it possible to distinguish the particles of a solute from those of a solvent in a suspension ?

Mass of solute (sodium chloride) = 36 g And, Mass of solvent (water) = 100 g So, Mass of solution = Mass of solute + Mass of solvent = 36 + 100 = 136 g Concentration of solution = Mass of solute / Mass of solvent 100 Now, putting these values of 'mass of solute' and 'mass of solution' in the above formula, we get: Concentration of solution = 36/136 100 = 26.47 percent. Therefore, the concentration of saturated solution sodium chloride at 293 K is 26.47 percent.

Pragya tested the solubility of three different substances at different temperatures and collected the data as given below(results are given in the following table, as grams of substance dissolved in 100 grams of water to form a saturated solution). (a) What mass of potassium nitrate would be needed to produce a saturated solution of potassium nitrate in 50 grams of water at 313 K? (b) Pragya makes a saturated solution of potassium chloride in water at 353K and leaves the solution to cool at room temperature. What would she observe as the solution cools? Explain. (c) Find the solubility of each salt at 293K . Which salt has the highest solubility at this temperature? (d) What is the effect of change of temperature on the solubility of a salt? (a) At 313 K 62 g of potassium nitrate dissolved in 100 g of water. So to produce a saturated solution of potassium nitrate in 50 g of water we need 1 0 0 6 2 ​ × 5 0 = 3 1 g of potassium nitrate. (b)Some soluble potassium chloride will separate out in the form of crystal at room temperature because the solubility of potassium chloride will decrease. (c) (i) Solubility of Potassium nitrate at 293 K is 32 g. (ii) Solubility of sodium chloride at 293 K is 36 g. (iii) Solubility of Potassium chloride at 293 K is 35 g. (iv) Solubility of Ammonium chloride at 293 K is 37 g. The solubility of Ammonium chloride is highest at this temperature. (d)The solubility of salt increases with the increase in temperature.