1. Suggest separation technique(s) one you need to employ separate the following mixtures :- a) Mercury & water ( give reason for your answer ) b) potassium chloride & ammonium chloride ( give reason for your answer ) c) common salt, water & sand ( give reason for your answer ) d) kerosene oil, water & sand ( give reason for your answer )
Answers
Answer:
a. separating funnel (Mercury is much denser than water)
b. sublimation (ammonium chloride undergoes sublimation)
c. filtration and evaporation (filtration to remove sand..... evaporation to remove water)
d. filtration and separating funnel (filtration to remove sand...... separating funnel to separate kerosene from water.....as kerosene is less dense than water)
Answer:
(a) Mercury and water are separated by decantation by using separating funnel as the separation of two immiscible liquids by a separating funnel depends on the difference in their densities. Mercury is heavier than water therefore, forms the lower layer and separated from water.
(b) Potassium chloride and ammonium chloride are separated by sublimation method because ammonium chloride being a sublimate, sublimes leaving behind the potassium chloride. Sublimation is the process in which a solid changes directly into vapours on heating and vapours change into solid on cooling without going in liquid state.
(c) Common salt, water and sand are separated by
(i) Decantation (or filtration) process is used to separate sand from common salt solution in water because common salt is soluble in water whereas sand is insoluble in water. Therefore, by filtration, sand will be separated as insoluble substance as residue and filtrate will be common salt solution in water.
ii) Evaporation process is used to separate common salt from water. Water evaporates and common salt remains as residue.
(d) (i) Decantation by using separating funnel is used to separate kerosene oil from salt solution inwater as they form separate layers (salt is soluble in water).
(ii) Evaporation is used to separate salt from water.