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प्रश्न
Draw neat labelled diagrams for two different experiments to prove that – hydrogen is lighter than air.
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उत्तर
Experiment 1
Procedure: Bubble hydrogen gas by means of a small pipe into a dish containing soap solution.
Observation: Soap bubbles filled with H2 rise upwards.
Conclusion: Hydrogen is lighter than air hence soap bubbles filled with hydrogen rise up.
Experiment 2
Procedure: Take two dry test tubes.
Test tube 'A' - Filled with hydrogen.
Test tube 'B' - Filled with air.
Place test tube 'B' over test tube 'A' and test the gas in the upper test tube 'B' with a glowing splinter.
Observation: A 'pop' sound is heard in test tube 'B'. [hydrogen burns with a 'pop' sound].
Conclusion: Hydrogen is lighter than air and has moved upwards displacing the air.
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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.
Name the chemicals required to prepare hydrogen gas in the laboratory.
Draw a neat and well-labelled diagram for the laboratory preparation of 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
Sodium liberates hydrogen when treated with cold .............
FILL IN THE BLANK
........................ zinc is preferred over pure zinc 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.
How would you show that hydrogen is lighter than air?
Starting from zinc how would you obtain hydrogen using Steam.
[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 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.
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.
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.
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.
Name a solution which absorbs the impurity – `"H"_2"S"`
