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प्रश्न
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.
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उत्तर
Addition of traces of copper [II] sulphate acts as catalyst and speeds up the reaction.
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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.
How would you show that hydrogen is a non-supporter of combustion?
Multiple Choice Question
In metal activity series the more reactive metals are at
FILL IN THE BLANK
........................ zinc is preferred over pure zinc in the laboratory preparation of hydrogen.
Give a test to identify hydrogen ?
How can these impurities be removed?
Under what conditions can hydrogen be made to combine with chlorine?
Name the products and write the equation for the reaction.
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?
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.
Complete and balance the equation:
[Laboratory method]
By action of dilute acid on zinc
Zinc - Zn + 2HCl → _____ + _____ [g]
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.
In the laboratory preparation of hydrogen from zinc and dil. acid. Give a reason for the following:
Hydrogen is not collected over air.
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.
The diagram represent the preparation and collection of hydrogen by a standard laboratory method.

Name a solution which absorbs the impurity – `"H"_2"S"`
The diagram represent the preparation and collection of hydrogen by a standard laboratory method.

State, why hydrogen is collected after all the air in the apparatus, is allowed to escape.
