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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.
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 ..................... than air.
Fill in the blank
Hydrogen reacts with metal oxides to form ............and....................
Multiple Choice Question
Water gas is a mixture of
MULTIPLE CHOICE QUESTIONS
Hydrogen burns in oxygen to form
- hydrogen sulphide
- nitrates
- water
- ammonia
FILL IN THE BLANK
........................... means ‘maker of water’ in Greek.
For laboratory preparation of hydrogen, give the following:
materials used
Give reason for the following:
The end of the thistle funnel should be dipped under acid.
Choose the correct option:
Elements which show unique nature in the preparation of hydrogen are:
How did the name 'hydrogen' originate?
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 metals not used in the lab. preparation of hydrogen?
sodium
Complete and balance the following reaction.
Zn + H2O →_____________ +___________
Complete and balance the following reaction.
Zn + HCl →_____________ +___________
‘Hydrogen is obtained by electrolysis of acidified water’.
Answer the following pertaining to the preparation of hydrogen by electrolysis,
Name the electrode –
- through which the current enters the electrolyte.
- at which hydrogen is liberated.
Select the correct options for the following statement:
The acid _____ is not Used in the laboratory preparation of hydrogen, using zinc and an acid.
Complete and balance the equation:
[General method]
Reactions of metals with steam
Aluminium - 2Al + 3H2O → ______+ _______ [g]
Complete and balance the equation:
[General method]
Reactions of metals with steam
Zinc - Zn + H2O → ______+ _______ [g]
Complete and balance the equation:
[Industrial Method - Bosch process]
- Step I - Production of water gas -
\[\ce{C + H2O->[1000°C]}\] [____ + ____] - Δ - Step II - Reduction of steam to hydrogen by carbon monoxide
\[\ce{CO + H2 + H2O->[450°C][Fe2O3]}\] _____ + ____ [g] - Step III - Removal of unreacted carbon dioxide and carbon monoxidefrom the above mixture
KOH + CO2 → _________ + ______
CuCl + CO + 2H2O → _______
State why hydrogen is not prepared in the laboratory by the action of sodium with cold water.
