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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.
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.
Name the following:
A metal which liberates hydrogen only when steam is passed over red hot metal.
Draw a neat and well-labelled diagram for the laboratory preparation of hydrogen.
TRUE \ FALSE
Lead reacts briskly with dilute hydrochloric acid to form hydrogen.
Give reason:
Apparatus for laboratory preparation of hydrogen should be airtight and away from a naked flame.
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.
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.
Give balanced equation for the following conversion:
Zinc to sodium zincate – using an alkali.
Give reason for the following:
In the laboratory preparation of hydrogen from zinc and dilute hydrochloric acid – the zinc used granulated zinc.
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:
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.
Name the following.
A gaseous reducing agent which is basic in nature.
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 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.
The diagram represent the preparation and collection of hydrogen by a standard laboratory method.
Name a gas other than hydrogen collected by the same method.
