Text Solution Solution : (a) Mass of potassium chloride in 100 g of water in saturated solution = 46 g <br> Mass of potassium chloride in 50 g of water in saturated solution = `((46 g))/((100 g)) xx (50g) = 23 g` <br> (b) When the solution is cooled, the solubility of salt in water will decrease. This means that upon cooling, it will start separating from the solution in crystalline form. Text Solution Solution : (a) When a saturated solution of potassium chloride prepared at `60^(@)`C is allowed to cool at room temperature, crystals of potassium chloride will be formed. <br> (b) Initially, sugar will obtained as water wil get evaporated. But on dry heating sugar gets charred and it turns back. <br> `C_(12)H_(22)O_(11)overset(triangle)(to)underset((Black))(12C)+11H_(2)Ouarr.` <br> (c) The black coloured compound, iron sulphide is formed when a mixture of iron filings and sulphur powder is heated strongly. <br> `underset("Iron filings")(Fe)+underset("Sulphur powder")(S) overset(triangle)(to) underset("Iron sulphide")(FeS)` Answer: (a) Sodium potassium chloride will separate out from the saturated solution when the temperature of the solution reduced from 60°C to room temperature. The solubility of the solid-state is affected by the change in temperature. (b) When aqueous sugar solution is heated first water gets evaporated up to some extent then sugar gets charred. (c) Iron combines with sulphur and forms iron sulphide (FeS). When iron filings and sulphur powder are mixed and heated they undergo a chemical reaction and form ferrous sulphide (FeS). It is a new substance which has properties entirely different from Fe and S.
warning Report Error Page 2
warning Report Error Page 3
warning Report Error Page 4
warning Report Error Page 5
warning Report Error Page 6
warning Report Error Page 7
warning Report Error Page 8
warning Report Error Page 9
warning Report Error Page 10
warning Report Error Page 11
warning Report Error Page 12
warning Report Error Page 13
warning Report Error Page 14
warning Report Error Page 15
warning Report Error Page 16
warning Report Error Page 17
warning Report Error Page 18
warning Report Error Page 19
warning Report Error Page 20Answer: (a) Alloys are homogeneous mixtures of metals, because (i) it shows the properties of its constituents, and (ii) it has variable composition., e.g., brass is considered a mixture, because it shows the properties of its constituents, copper and zinc, and it has a variable composition (amount of Zn in brass can vary from 20 to 35 per cent). (b) A solution is generally a liquid, not always. It may involve solids and gases also, e.g., alloys are solution of solid in solid. Air is solution of gases in gases. (c) Colloidal solutions are heterogeneous in nature, though they appear to be homogeneous, Page 21
warning Report Error Page 22
warning Report Error Page 23
warning Report Error Page 24
warning Report Error Page 25
warning Report Error Page 26
warning Report Error |