Advertisements
Advertisements
प्रश्न
Explain how, nitrogen , oxygen and argon gases are separated from air.
Advertisements
उत्तर
Nitrogen, oxygen and argon are separated from air by fractional distillation. Following are the steps followed to separate these gases from air:
- Air is first filtered to remove the dust particles, spores etc. Subsequently water vapours and carbon dioxide are removed.
- Air is subjected to high pressure and then cooled. This air is then allowed to expand in a chamber which causes further cooling of the air.
- This process is repeated to cool the air further. Ultimately, the air becomes so cold that it turns into a liquid.
- This liquid air is then fed into a fractionating column from its bottom end and is cooled slowly.
- Liquid nitrogen boils off first to nitrogen gas as the boiling point of nitrogen is lowest at -196°C.
- Liquid argon boils off at a boiling point of -186°C.
- Liquid oxygen boils off last as it has highest boiling point among all three (around -183°C).
Figure 84. Separation of the major gases of air.
APPEARS IN
संबंधित प्रश्न
Define the term matter. What is it composed of?
When a gas jar containing air is inverted over a gas jar containing bromine vapour, the red-brown bromine vapour diffuse into air. Explain how bromine vapour diffuse into air.
The best evidence for the existence and movement of particles in liquids was provided by :
Name a non-metal which is a good conductor of electricity.
Name two solid, two liquid and two gaseous elements at the room temperature.
Give reason why copper metal is used for making electric wires.
Choose the correct answer.
A 5 per cent sugar solution means that :
What is meant by a solution?
When the solid A is added to water, it dissolves with the evolution of a lot of heat and making little explosions to form two products B and C. The properties of products B and C are entirely different from those of solid A as well as water. Moreover, products B and C cannot be reconverted into solid A and water. When another solid D is added to water, it dissolves with the absorption of a little heat to form a product E which cools down. The product E shows the properties of both, solid D as well as water. Moreover, product E can be converted into solid D and water.
(a) What type of change occurs when solid A is dissolved in water ? Why ?
(b) What type of change occurs when solid D is dissolved in water ? Why ?
(c) Name a metal which you think could behave like solid A. Also name the products B and C.
(d) Name the solid D if it is the one which is used in making ordinary dry cells.
(e) Name the process by which D can be recovered from E.
Which method is better for recovering sugar from sugar solution : evaporation or crystallisation ? Give reason
for your answer.
What is fractional distillation ? What is the use of fractionating column in fractional distillation ?
Pure copper sulphate can be obtained from an impure sample by the process of :
The correct increasing order of the boiling points of liquid oxygen, liquid argon and liquid nitrogen present in liquid air is :
The non S I and S I units of some physical quantities are given in column A and column B respectively. Match the units belonging to the same physical quantity:
| (A) | (B) | ||
| (a) | degree celsius | (i) | kilogram |
| (b) | centimetre | (ii) | pascal |
| (c) | gram per centimetre cube | (iii) | metre |
| (d) | bar | (iv) | kelvin |
| (e) | milligram | (v) | kilogram per metre cube |
Non-metals are usually poor conductors of heat and electricity. They are non-lustrous, non-sonorous, non-malleable and are coloured.
Name a non-metal which exists as a liquid at room temperature.
Celsius scale is a scale of temperature in which zero represents the melting point of ice and 100 represents the boiling point of water.
Which statement is not correct for a mixture
Define the term matter.
