Advertisements
Advertisements
प्रश्न
Draw neat labelled diagrams for two different experiments to prove that – hydrogen is lighter than air.
Advertisements
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.
APPEARS IN
संबंधित प्रश्न
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.
How is hydrogen gas collected? Why?
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?
How can these impurities be removed?
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.
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:
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.
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 complete apparatus is air-tight.
In the laboratory preparation of hydrogen from zinc and dil. acid. Give a reason for the following:
Hydrogen is not collected over air.
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.
