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प्रश्न
Give reason for the following:
Though hydrogen is lighter than air it cannot be collected by downward displacement of air.
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उत्तर
Since hydrogen is lighter than air. it is possible to collect the gas by downward displacement of air. But it is not safe to do so since a mixture of hydrogen and air can lead to an explosion.
संबंधित प्रश्न
Hydrogen is ______ than air.
Multiple Choice Question
Water gas is a mixture of
FILL IN THE BLANK
........................... means ‘maker of water’ in Greek.
FILL IN THE BLANK
In electrolysis of water, dilute sulphuric acid is added to increase ..................of water.
TRUE \ FALSE
Hydrogen does not combine with nitrogen under ordinary conditions.
Which metal is preferred for the preparation of hydrogen?
from water?
What is noticed if the products are not allowed to escape?
For laboratory preparation of hydrogen, give the following:
chemical equation
Why nitric acid is not used in the preparation of hydrogen?
Hydrogen may be prepared in the laboratory by the action of a metal on an acid.
Which of the acids dilute sulphuric, concentrated sulphuric, dilute nitric acid and concentrated nitric acid would you choose? Explain why you would not use the acids you reject.
Complete and balance the following reaction.
Na + H2O →_____________ +___________
Complete and balance the following reaction.
Ca + H2O →_____________ +___________
Complete and balance the following reaction.
Zn + NaOH →_____________ +___________
Correct the following statement:
Hydrogen is separated from CO by passing the mixture through caustic potash solution.
Complete and balance the equation:
[General method]
Reactions of active metals - cold water
Sodium - 2Na + 2H2O → ______+ _______ [g]
Complete and balance the equation:
[General method]
Reactions of metals with dilute acids
Magnesium - Mg + 2HCl → ______+ _______ [g]
Complete and balance the equation:
[General method]
Reactions of metals with dilute acids
Iron - Fe + 2HCl → ______ + _______ [g]
Complete and balance the equation:
[General method]
Reactions of metals - alkali [conc. soln.]
Aluminium - 2Al + 2NaOH + 2H2O → ______ + _______ [g]
2Al + 2KOH + 2H2O → _____ + _____ [g]
Select the correct answer to the reactant added, to give the product in the preparation of hydrogen gas.
\[\ce{NaAlO2 + H2}\]
Give a balanced equation for the following conversion.
\[\ce{CO + H2<-H2O->CO2 + H}\]
