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प्रश्न
Give a test to differentiate between two gas jars – one containing pure hydrogen and the other hydrogen-air mixture.
Compare the combustibility of –
(a) pure hydrogen
(b) hydrogen-air mixture.
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उत्तर १
When a burning splinter is brought near the gas jar containing, pure H2 bums with pale blue flame quietly.
H2 + Oxygen mixture bums with explosion.
उत्तर २
Combustibility of :
(a) Pure hydrogen: Bums quietly in air with a pale blue flame forming water
2H2 + O2 → 2H2O
(b) Hydrogen air mixture: It explodes on burning.
संबंधित प्रश्न
Indicate which of the following statement is true and which is false:
The hydrogen molecule is monovalent.
Hydrogen is combustible as well as a supporter of combustion.
Complete and balance the following equation:
H2+____________→ 2HCI
Give reason for the following:
A pop sound produced when hydrogen is burnt?
State four uses of hydrogen:
Multiple Choice Question
Hydrogen is
MULTIPLE CHOICE QUESTIONS
The name hydrogen was given by
- Cavendish
- Lavoisier
- Haber
- none of these
MULTIPLE CHOICE QUESTIONS
Which is the lightest of all elements?
- hydrogen
- helium
- lithium
- none of these
FILL IN THE BLANK
The compounds of carbon and hydrogen are called .................
FILL IN THE BLANK
Ammonia is used to make ................
Write the balanced equation and give your observation when the following metal reacts:
Calcium with cold water
Write the balanced equation and give your observation when the following metal reacts:
Magnesium with boiling water
Using a burning candle and a jar of hydrogen – how would you prove experimentally that Hydrogen does not support combustion.
With reference to the equation : Cl2 + H2S → 2HCl + S pertaining to a redox reaction – select the correct answer.
Chlorine is ______ to HCl.
With reference to the equation : Cl2 + H2S → 2HCl + S pertaining to a redox reaction – select the correct answer.
Hydrogen sulphide is ______ to sulphur since the reaction involves ______ of hydrogen.
Give balanced equation for the following conversion:
Nitrogen to a basic gas – using hydrogen.
Select the correct options for the following statement:
The gas which has now replaced hydrogen in air balloons is ___.
Give a chemical test to distinguish between the following gases:
Hydrogen and oxygen
What do the following symbols [or formula] denote : 2H ; H2 ; H+. [two atoms, molecule, ion]
Write a correctly balanced equation for the following “word equation”:
calcium + water → calcium hydroxide + hydrogen
When steam is passed over red-hot iron, magnetic oxide of iron and hydrogen are obtained. “The reaction between steam and red-hot iron is a Reversible Reaction.” What is meant by this statement.
Name a gas which burns in air or oxygen forming water.
Write correctly the balanced equation for the following:
‘When zinc filings are added to a concentrated solution of sodium hydroxide’.
What do you observe when a piece of sodium is dropped into cold water?
Complete and balance the following equations:
Al + NaOH + ____ → ____ + ____
Select the correct answer from the symbol in the bracket.
The element, which like hydrogen has one valence electron.
