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प्रश्न
How is hydrogen gas collected? Why?
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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?
Name the following:
A metallic oxide which can be reduced into metal by hydrogen.
FILL IN THE BLANK
Sodium liberates hydrogen when treated with cold .............
FILL IN THE BLANK
........................ zinc is preferred over pure zinc in the laboratory preparation of hydrogen.
Why is granulated zinc preferred in the laboratory preparation of hydrogen?
Give a test to identify hydrogen ?
How can these impurities be removed?
Give reason:
Apparatus for laboratory preparation of hydrogen should be airtight and away from a naked flame.
How would you show that hydrogen is lighter than air?
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 addition of traces of copper [II] sulphate to the reaction medium.
Give balanced equation for the following conversion:
Acidified water to hydrogen – by electrolysis.
Give reason for the following:
Copper does not displace hydrogen from dilute hydrochloric acid, but zinc does.
Give a balanced equation for the following conversions sodium plumbite from lead.
Give a balanced equation for the following conversions sodium aluminate from aluminium.
In the laboratory preparation of hydrogen from zinc and dil. acid. Give a reason for the following:
Dilute nitric acid is not preferred as the reactant acid.
Name the following.
A gaseous reducing agent which is basic in nature.
The diagram represent the preparation and collection of hydrogen by a standard laboratory method.
Name a solution which absorbs the impurity – `"H"_2"S"`
