Suggest separation techniques a) kerosene oil, …

(a) Kerosene oil, water, and salt - The principle that can be used to separate kerosene oil from salt solution is that immiscible liquids separate out in layers depending on their densities. Water and kerosene oil are immiscible liquids. A separating funnel can be used to separate the two. Pour the mixture of kerosene oil and salt water in a separating funnel. Leave it undisturbed for sometime so that separate layers of kerosene oil and salt water are formed. Salt water is denser and will form a layer at the bottom. Open the stopcock of the separating funnel and pour out the lower layer of water in a container carefully. Close the stopcock of the separating funnel as the oil reaches the stop-****. The separating funnel will have kerosene oil only. The volatile component (solvent) can be separated from its non-volatile solute (salt) by the method of evaporation. Refer Fig.2.6 on page 20 of the NCERT Book.

(b) Mercury and water - Mercury is the only metal that is liquid at room temperature. Mercury also has a very low solubility in water -- the cohesive forces between mercury atoms are much stronger than those between water molecules and mercury atoms. The relative density of mercury is 13.56; it is 13.56 times as dense as water. Thus, a separating funnel can be used to separate the two liquids. Mercury will form the lower layer and water will form the upper layer.

(c) Potassium chloride and ammonium chloride - Ammonium chloride (NH₄Cl) changes directly from solid to gaseous state on heating. So, to separate such mixtures that contain a sublimable volatile component (ammonium chloride in this case) from a non-sublimable component (Potassium chloride in this case), the sublimation process is used. Vapours of ammonium chloride solidify on cooling. Refer Fig.2.7 on page 20 of the NCERT Book.