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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
Fill in the blank
Hydrogen is ...................soluble in water.
How do different metals displace hydrogen from water? Explain with the help of equations.
What is noticed if the products are not allowed to escape?
Hydrogen can be prepared with the help of cold water. Give a reaction of hydrogen with:
A monovalent metal
Hydrogen may be prepared in the laboratory by the action of a metal on an acid.
Which of the metals copper, zinc, magnesium or sodium would be the most suitable?
Why are the following metal not used in the lab. preparation of hydrogen?
iron
Complete and balance the following reaction.
Fe + H2O →_____________ +___________
Complete and balance the following reaction.
Zn + HCl →_____________ +___________
Complete and balance the following reaction.
Al + H2SO4 →_____________ +___________
‘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’.
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 active metals - cold water
Sodium - 2Na + 2H2O → ______+ _______ [g]
Complete and balance the equation:
[General method]
Reactions of metals with steam
Iron - 3Fe + 4H2O ⇌ ______+ _______ [g]
Complete and balance the equation:
[General method]
Reactions of metals with dilute acids
Iron - Fe + 2HCl → ______ + _______ [g]
Name an element whsich reacts violently with water at room temperature.
Account for the following fact:
Though lead is above hydrogen in the activity series, it does not react with dilute hydrochloric acid or dilutes sulphuric acid.
State why hydrogen is not prepared in the laboratory by the action of sodium with cold water.
State the reactant added to hydrogen to obtain the respective product in following case.
Ammonia
Select the correct answer to the reactant added, to give the product in the preparation of hydrogen gas.
\[\ce{Al2(SO4)3 + H2}\]
