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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
Multiple Choice Question
The metal which reacts with cold water to produce hydrogen is
MULTIPLE CHOICE QUESTIONS
Hydrogen burns in oxygen to form
- hydrogen sulphide
- nitrates
- water
- ammonia
FILL IN THE BLANK
........................... means ‘maker of water’ in Greek.
What is noticed if the products are not allowed to escape?
Complete the following word equation:
Sodium hydroxide + zinc → hydrogen + _________
For laboratory preparation of hydrogen, give the following:
materials used
Hydrogen may be prepared in the laboratory by the action of a metal on an acid.
Which of the acids dilute sulphuric, concentrated sulphuric, dilute nitric acid and concentrated nitric acid would you choose? Explain why you would not use the acids you reject.
Complete and balance the following reaction.
Fe + H2O →_____________ +___________
Select the correct options for the following statement:
The metallic compound formed when a metal above aluminium in the activity series reacts with steam.
Select the correct options for the following statement:
The product formed on combustion of hydrogen in air is ___.
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 dilute acids
Zinc - Zn + 2HCl → ______ + _______ [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]
Name an element whsich reacts violently with water at room temperature.
How did the name ‘hydrogen’ originate? How does hydrogen occur in the combined state?
Give a balanced equation for obtaining hydrogen from?
Steam using a metal – and the reaction is reversible.
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.
\[\ce{MgO + H2}\]
