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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.
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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
Multiple Choice Question
Water gas is a mixture of
TRUE \ FALSE
reacts with hot water to form copper oxide and hydrogen.
MATCH THE COLUMNS
| column A | column B |
| 1. `""2H_2 + O_2 → 2H_2O` | A. This reaction is not possible |
| 2. `""H_2+CI_2 →2HCI` | B.This reaction is exothermic to the extent of explosion |
| 3.`""ZaO+ H^2→Zn +H_2O` | C.This reaction is known as Haber process |
| 4.`""Cu + H_2SO^4 → CuSO_4 + H_2 ` | D.This reaction illustrates the reducing property of bydrogen |
| 5.`""N_2 +3H_2 → 2NH_3 +heat ` | E. This reaction takes place in diffused sunlight |
| F. This reaction is a method of preparation of hydrogen |
Which metal is preferred for the preparation of hydrogen?
from acid?
What is noticed if the products are not allowed to escape?
Give a reason for the following:
Zinc granules are used in the lab preparation of hydrogen.
Why are the following metal not used in the lab. preparation of hydrogen?
iron
Complete and balance the following reaction.
Zn + H2O →_____________ +___________
Complete and balance the following reaction.
Fe + H2O →_____________ +___________
‘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 neutral liquid.
Starting from hydrogen gas how would you obtain a basic gas.
Select the correct options for the following statement:
A foul smelling gas formed when hydrogen reacts with a molten non-metal, is ___.
Complete and balance the equation:
[General method]
Reactions of metals with dilute acids
Zinc - Zn + 2HCl → ______ + _______ [g]
Complete and balance the equation:
[General method]
Reactions of metals - alkali [conc. soln.]
Lead - Pb + 2NaOH → ______ + _______ [g]
Name an element whsich reacts violently with water at room temperature.
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 → _______
How did the name ‘hydrogen’ originate? How does hydrogen occur in the combined state?
Give a balanced equation for the following conversion.
\[\ce{MgCl2<-HCl->FeCl2}\]
Give a balanced equation for the following conversion.
\[\ce{KAlO2<-KOH->K2ZnO2}\]
