Advertisements
Advertisements
प्रश्न
A mixture has a variable composition. Give three other reasons why air is considered a mixture and not a compound.
Advertisements
उत्तर
Air is a mixture because :
- Air has no formula, a mixture has no formula whereas the compound has a formula.
- No energy changes are involved to form air from various gases.
- When air is formed out of its constituents no change in mass nor change in volume takes place.
- Properties of air vary from place to place and from time to time. i.e. there is more CO2 in towns as compared to villages where more oxygen prevales as compared to towns.
- Components of air can be separated by simple physical methods.
संबंधित प्रश्न
Match the statements in Column A, with those in Column B.
| Column A | Column B |
| 1. Largest Constituent of air, which dilutes the activity of oxygen. |
(a) Oxygen |
| 2. A gas used for filling weather observation balloons. | (b) carbon acid |
| 3. An acid formed by the dissolution of sulphur dioxide gas in water. | (c) Sulphur acid |
| 4. An acid formed by the dissolution of carbon dioxide in water. | (d) Helium |
| 5. A gas vital for respiration. | (e) Nitrogen |
Define the following:
Respiration
How is air useful to agriculture?
Mention five causes of air pollution.
Name three greenhouse gases.
Fill in the blank
Polluted air is harmful to ____.
State whether the following statement is true or false.
The pressure exerted by air is called atmospheric pressure.
Draw a neat labelled diagram for the following experiment.
To determine the component of air used up in burning, by using phosphorus and a bell jar.
Name a device which uses wind energy to generate electricity.
Cool and soothing wind: Breeze.
uproot trees wind: ______.
