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प्रश्न
What do you observe when a piece of sodium is dropped into cold water?
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उत्तर
When a piece of sodium metal dropped in cold water we observe: Sodium floats on water surface melts forming a silvery globule which darts about the surface of water catches fire and burns with golden yellow flame.
Bubbles of hydrogen evolve and solution is soapy, slightly warm (alkaline) hence turns red litmus blue.
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संबंधित प्रश्न
Indicate which of the following statement is true and which is false:
The hydrogen molecule is monovalent.
Indicate which of the following statement is true and which is false:
Hydrogen gas is easily liquefiable.
Give reason for the following:
A pop sound produced when hydrogen is burnt?
Give reason for the following:
Helium replaced hydrogen in weather observation balloons?
Define catalytic hydrogenation.
Multiple Choice Question
Equal volumes of hydrogen and chlorine are exposed to diffused sunlight to prepare
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In nature, hydrogen occurs as a .................. molecule represented as H2
Write the balanced equation and give your observation when the following metal reacts:
Magnesium with boiling water
With reference to the equation : Cl2 + H2S → 2HCl + S pertaining to a redox reaction – select the correct answer.
Chlorine is ______ to HCl.
Give balanced equation for the following conversion:
Nitrogen to a basic gas – using hydrogen.
Give a chemical test to distinguish between the following gases:
Ammonia and hydrogen chloride
Write a correctly balanced equation for the following “word equation”:
calcium + water → calcium hydroxide + hydrogen
How can you obtain hydrogen from sodium hydroxide [not by electrolysis].
Write balanced equation for the following reaction:
magnesium + dil. hydrochloric acid → ___
Name a gas which burns in air or oxygen forming water.
Write a correctly balanced equation for the following:
When steam is passed over red hot iron.
Write correctly the balanced equation for the following:
‘When zinc filings are added to a concentrated solution of sodium hydroxide’.
Describe one chemical test applied to the following gases, which would enable you to distinguish between them :‘carbon monoxide and hydrogen’.
Describe briefly, with equations, the Bosch Process for the large scale production of hydrogen.
