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Question
Give reason for the following:
Though hydrogen is lighter than air it cannot be collected by downward displacement of air.
Solution
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.
RELATED QUESTIONS
A metal ______ hydrogen in the reactivity series gives hydrogen with ______.
Multiple Choice Question
Water gas is a mixture of
Why hot concentrated sulphuric acid is not used in the preparation of hydrogen?
Give a reason for the following:
Zinc granules are used in the lab preparation of hydrogen.
Why are the following metals not used in the lab preparation of hydrogen?
calcium
Why are the following metals not used in the lab. preparation of hydrogen?
sodium
Complete and balance the following reaction.
Fe + H2O →_____________ +___________
Correct the following statement:
Hydrogen is separated from CO by passing the mixture through caustic potash solution.
‘Hydrogen is obtained by electrolysis of acidified water’.
Answer the following pertaining to the preparation of hydrogen by electrolysis,
The meaning of the term ‘electrolysis’ and ‘electrolyte’.
Starting from hydrogen gas how would you obtain a basic gas.
Starting from hydrogen gas how would you obtain a metal by reduction of its heated oxide.
Select the correct options for the following statement:
The metallic compound formed when a metal above aluminium in the activity series reacts with steam.
Complete and balance the equation:
[General method]
Reactions of metals with steam
Magnesium - Mg + H2O → ______+ _______ [g]
Complete and balance the equation:
[General method]
Reactions of metals - alkali [conc. soln.]
Lead - Pb + 2NaOH → ______ + _______ [g]
Account for the following fact:
Potassium and sodium are not used to react with dilute ‘hydrochloric acid or dilute sulphuric acid in the laboratory preparation of hydrogen.
State the electronic configuration of hydrogen [at. no. 1].e
Give a reason why hydrogen can be placed in group 1 [1A] and group 17 [VIIA] of the periodic table.
State the condition and give balanced equation for the conversion of water gas to hydrogen – in the Bosch process.
Select the correct answer to the reactant added, to give the product in the preparation of hydrogen gas.
\[\ce{Ca(OH)2 + H2}\]
Give a balanced equation for the following conversion.
\[\ce{KAlO2<-KOH->K2ZnO2}\]
Give a reason for the following.
Granulated zinc is preferred to metallic zinc in the preparation of hydrogen using dilute acid.
