How can the components of following mixture be separated:
(i) kerosene oil and water
(ii) Salt and Ammonium chloride
(iii) Pure Copper sulphate from impure sample
(iv) Dyes in black ink
please write 400-500 words please please please..
Answers
Answer:
i) by decantation
Kerosene oil and water do not mix with each other and form two separate layers. The mixture separates into two layers according to their densities. The heavier liquid (water) forms the lower layer whereas the lighter liquid forms the upper layer (kerosene). Thus, the water is first collected in the beaker.
ii) by sublimation
We can seperate the mixture of ammonium chloride and salt through sublimation process. The process by which the change of gaseous state directly to solid state without going through liquid state, and vice versa. Sublimation is the method of separation used to separate a mixture of salt and ammonium chloride.
iii) by crystallization
Copper sulphate can be obtained from an impure sample by crystallisation. The impurities will remain in the mother liquor whereas the pure copper sulphate will crystallize out.
iv) by paper chromatography
A paper chromatography experiment can be performed to separate dyes present in black ink in the following manner:
1. Take a thin, long strip of filter paper and draw a 3 cm long line from one end with a pencil.
2. Put a small drop of black ink at the centre of the pencil line and let it dry.
3. When it is dry, lower the paper strip into a tall glass jar containing some water in its lower part (keep the pencil line at the bottom). The upper end of the paper strip should be attached to a glass rod with cellotape. The lower end of the paper strip should dip in water but the pencil line should stay above the water level in the jar.
4. The water will gradually rise up the filter paper strip by capillary action. As it moves up it will take along the dyes present in the ink. The dye which is more soluble in water will dissolve first, rise faster and produce a coloured spot on the paper at a higher position. The less soluble dyes will dissolve a little later, rise slowly and form coloured spots at lower heights. In this way all the dyes present in the black ink will get separated and form separate coloured spots.
5. Remove the filter paper strip from the jar when the water reaches the top end of the strip and let it dry. The paper with the separate coloured spots is known as a chromatogram.