Science
Which separation techniques will you apply for the separation of the following?
(a) Sodium chloride from its solution in water.
(b) Ammonium chloride from a mixture containing sodium chloride and ammonium chloride.
(c) Small pieces of metal in the engine oil of a car.
(d) Different pigments from an extract of flower petals.
(e) Butter from curd.
(f) Oil from water.
(g) Tea leaves from tea.
(h) Iron pins from sand.
(i) Wheat grains from husk.
(j) Fine mud particles suspended in water.
Answer
(a) Sodium chloride from its solution in water — Evaporation
(b) Ammonium chloride from a mixture containing sodium chloride and ammonium chloride — Sublimation
(c) Small pieces of metal in the engine oil of a car — Filtration
(d) Different pigments from an extract of flower petals — Chromatography
(e) Butter from curd — Centrifugation
(f) Oil from water — By a separating funnel
(g) Tea leaves from tea — By using stainer for filtration
(h) Iron pins from sand — By using a magnet
(i) Wheat grains from husk — Sedimentation/winnowing
(j) Fine mud particles suspended in water — Sedimentation/decantation
Related Questions
Classify the following as chemical or physical changes:
- Cutting of trees
- Melting of butter in a pan
- Rusting of almirah
- Boiling of water to form steam
- Passing of electric current through water and the water breaking down into hydrogen and oxygen gases.
- Dissolving common salt in water
- Making a fruit salad with raw fruits, and
- Burning of paper and wood
Try segregating the things around you as pure substances and mixtures.
Write the steps you would use for making tea. Use the words solution, solvent, solute, dissolve, soluble, insoluble, filtrate, and residue.
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 a substance dissolved in 100 grams of water to form a saturated solution).
Substance Dissolved Temperature in K 283 293 313 333 353 Solubility Potassium nitrate 21 32 62 106 167 Sodium chloride 36 36 36 37 37 Potassium chloride 35 35 40 46 54 Ammonium chloride 24 37 41 55 66 (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 353 K 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 293 K. Which salt has the highest solubility at this temperature?
(d) What is the effect of change of temperature on the solubility of a salt?