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प्रश्न
In the laboratory preparation of hydrogen from zinc and dil. acid. Give a reason for the following:
Hydrogen is not collected over air.
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उत्तर
Air forms an explosive mixture with H2.
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संबंधित प्रश्न
Indicate which of the following statement is true and which is false:
Nitric acid cannot be used to prepare hydrogen by its action on active metals.
Indicate which of the following statement is true and which is false:
Zinc can liberate hydrogen from water, acid and alkali solution.
Name the following:
A metallic oxide which can be reduced into metal by hydrogen.
Draw a neat and well-labelled diagram for the laboratory preparation of hydrogen.
Multiple Choice Question
In metal activity series the more reactive metals are at
Why is granulated zinc preferred in the laboratory preparation of hydrogen?
Name the impurities present in hydrogen prepared in the laboratory.
How can these impurities be removed?
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.
Starting from zinc how would you obtain hydrogen using an alkali.
[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.
Give reason for the following:
Copper does not displace hydrogen from dilute hydrochloric acid, but zinc does.
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:
The lower end of the thistle funnel should dip below the level of the acid in the flask.
Give a reason for the following.
Nitric acid in the dilute form is not used in the laboratory preparation of hydrogen from metals.
Select the correct answer from the symbol in the bracket.
The element which forms a diatomic molecule.
The diagram represent the preparation and collection of hydrogen by a standard
laboratory method.

State what is added through the thistle funnel ‘Y’
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.

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