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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.
Which metal is preferred for the preparation of hydrogen?
from acid?
Complete the following word equation:
Sodium hydroxide + zinc → hydrogen + _________
For laboratory preparation of hydrogen, give the following:
method of collection
For laboratory preparation of hydrogen, give the following:
chemical equation
Which test should be made before collecting hydrogen in a gas jar?
Hydrogen can be prepared with the help of cold water. Give a reaction of hydrogen with:
A monovalent metal
Why are the following metals not used in the lab preparation of hydrogen?
calcium
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.
Starting from hydrogen gas how would you obtain a basic gas.
Select the correct options for the following statement:
The metallic compound formed when a metal above aluminium in the activity series reacts with steam.
On heating which of the following substances i.e. copper carbonate, zinc carbonate, washing soda, copper sulphate, zinc nitrate, copper nitrate, lead nitrate, ammonium chloride and ammonium dichromate – relate to the reaction given below.
A white substance which leaves an amphoteric oxide as a residue [whose colour varies in the heated and in the cold state] and evolves a gas which turns lime water milky.
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]
Complete and balance the equation:
[General method]
Reactions of metals - alkali [conc. soln.]
Aluminium - 2Al + 2NaOH + 2H2O → ______ + _______ [g]
2Al + 2KOH + 2H2O → _____ + _____ [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 → _______
Give a balanced equation for obtaining hydrogen from?
Steam using a trivalent metal
State the reactant added to hydrogen to obtain the respective product in following case.
Water
Select the correct answer to the reactant added, to give the product in the preparation of hydrogen gas.
\[\ce{MgO + H2}\]
