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प्रश्न
How can these impurities be removed?
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उत्तर
- The impurities can be removed from hydrogen by passing it through
- Silver nitrate solution to remove arsine and phosphine.
AsH3 + 6AgNO3 → Ag3As + 3AgNO3 + 3HNO3
PH3 + 6AgNO3 → Ag3P + 3AgNO3 + 3HNO3
- Lead nitrate solution to remove hydrogensulphide.
Pb(NO3)2 + H2S → Pbs + 2HNO3
- Caustic potash solution to remove sulphur dioxide, carbon dioxide and oxides of nitrogen.
SO2 + 2KOH → K2SO3 + H2O
CO2 + 2KOH→ K2CO3+ H2O
2NO2 + 2KOH →KNO2 + KNO3 + H2O
- A drying agent used to dry the gas. Common drying agents such as fused calcium chloride, caustic potash stick and phosphorus pentoxide remove water vapor.
So, the gas is purified and dried and then collected over mercury because mercury does not react with it.
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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.
How is hydrogen gas collected? Why?
TRUE \ FALSE
Lead reacts briskly with dilute hydrochloric acid to form hydrogen.
Why is granulated zinc preferred in the laboratory preparation of hydrogen?
Give a test to identify hydrogen ?
Give reason:
Apparatus for laboratory preparation of hydrogen should be airtight and away from a naked flame.
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 reason for the following:
Copper does not displace hydrogen from dilute hydrochloric acid, but zinc does.
Give reason for the following:
In the laboratory preparation of hydrogen from zinc and dilute hydrochloric acid – the zinc used granulated zinc.
In the laboratory preparation of hydrogen from zinc and dil. acid. Give a reason for the following:
The complete apparatus is air-tight.
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.
Give a reason for the following.
Nitric acid in the dilute form is not used in the laboratory preparation of hydrogen from metals.
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.
Name a gas other than hydrogen collected by the same method.
