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प्रश्न
What is chromatography ? State its two applications.
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उत्तर
Chromatography is a technique used for separating two or more dissolved solids, which are present in the solution in small quantities.
Separation is based on the fact that two or more substances are soluble in the solvent but their solubility is different.
This technique has various important applications:
- To separate dyes present in black ink
- It is used in forensic science to detect and identify the trace amounts of poison present in the stomach.
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संबंधित प्रश्न
What are the two conditions for the interconversion of states of matter ?
Classify the following into elements, compounds and mixtures:
- Sodium
- Soil
- Sugar solution
- Silver
- Calcium carbonate
- Tin
- Silicon
- Coal
- Air
- Soap
- Methane
- Carbon dioxide
- Blood
What is meant by saying that non-metals are brittle ?
Classify the following as elements or compounds :
Iron, Iron sulphide, Sulphur, Chalk, Washing soda, Sodium, Carbon, Urea
There is a large group of materials P which can be divided into three groups Q, R and S on the basis of their properties. The substances belonging to group Q can be solids, liquids or gases. The solids belonging to group Q are usually electrical insulators. Most of the substances of group R are solids which are good conductors of electricity. The substances belonging to group S are neither insulators like Q nor good conductors like R. The properties of S are intermediate between those of Q and R.
- What could the group of materials P be ?
- Name the substances Q. Give two examples of such substances.
- Name the substances R. Write two examples of such substances.
- Name the substances S. Give two examples of such substances.
- Out of Q, R and S, which substances are malleable and ductile ?
A, B and C are all liquids. Liquid A has a comparatively low boiling point. On heating, liquid A vaporises completely without leaving behind any residue. Liquid A is being used increasingly as a fuel in motor vehicles either alone or by mixing with petrol. Liquid B has a very high boiling point. It also vaporises completely on heating, without leaving any residue. Liquid B is a conductor of electricity and used in making thermometers. Liquid C has a moderate boiling point. On heating, liquid C vaporises leaving behind a white solid D which is used in cooking vegetables. The condensation of vapours from C give a liquid E which turns anhydrous CuSO4 to blue.
(a) Which liquid could be an element ? Name this element.
(b) Which liquid could be a mixture ? Name this mixture.
(c) Which liquid could be a compound ? Name this compound.
(d) What could the solid D be ?
(e) What do you think is liquid E ?
Fill in the following blank :
A colloid is a ..............mixture and its components can be separated by the technique known as ...............
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- a glass bottle breaking
- coal burning in air
- making a cake
- wool being knitted into a sweater
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Name the process by which all the dye can be recovered from black ink.
Which technique is used in a washing machine to squeeze out water from wet clothes while drying ?
How would you obtain sodium chloride from a mixture of sodium chloride and sulphur without using water ?
Naphthalene can be separated from sand :
Which one of the following scrap metal cannot be separated by magnetic separation ?
All the matter made of ______.
Rusting of an article made up of iron is called
Which statement is not correct for a mixture
The pressure of gases does not depend on the temperature of the gas and the volume it occupies.
