Advertisements
Advertisements
Question
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.
Advertisements
Solution
Otherwise gas produced will escape through thistle funnel.
RELATED QUESTIONS
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.
Give reason for the following:
Nitric acid not used for the preparation of hydrogen gas?
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.
How is hydrogen gas collected? Why?
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.
Why is granulated zinc preferred in the laboratory preparation of hydrogen?
Give a test to identify hydrogen ?
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?
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.
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.
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.
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.
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.
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.
