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प्रश्न
How is hydrogen gas collected? Why?
उत्तर
- Hydrogen is sparingly soluble in water. Therefore, as it is collected over water, it picks up moisture. Dry hydrogen gas is obtained when it is collected over mercury.
- Since hydrogen is lighter than air, it is possible to collect the gas by downward displacement of air. But it is not safe to do so since a mixture of hydrogen and air can lead to an explosion.
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संबंधित प्रश्न
Give reason for the following:
Nitric acid not used for the preparation of hydrogen gas?
Why is granulated zinc preferred in the laboratory preparation of hydrogen?
Give a test to identify hydrogen ?
Starting from zinc how would you obtain hydrogen using a dilute acid.
[Give balanced equation & name the product formed in the case other than hydrogen].
Name a metal which will not react with the reactants above to give hydrogen.
In the laboratory preparation of hydrogen from zinc & dilute hydrocholoric acid – state a reason for the collecting the hydrogen by downward displacement of water and not air & collecting it after all the air in the apparatus is allowed to escape.
Draw neat labelled diagrams for two different experiments to prove that – hydrogen is lighter than air.
Give balanced equation for the following conversion:
Zinc to sodium zincate – using an alkali.
Give balanced equation for the following conversion:
Acidified water to hydrogen – by electrolysis.
In the laboratory preparation of hydrogen from zinc and dil. acid. Give a reason for the following:
The complete apparatus is air-tight.
The diagram represent the preparation and collection of hydrogen by a standard laboratory method.
State what difference will be seen if pure zinc is added in the distillation flask ‘X’ instead of granulated zinc.
