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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:
Helium replaced hydrogen in weather observation balloons?
Define catalytic hydrogenation.
Multiple Choice Question
Hydrogen is
FILL IN THE BLANK
Hydrogen is present abundantly in the ................
Give the balanced equation of the reaction.
Correct the following statement:
Hydrogen is dried by passing it through conc. H2SO4.
Using a burning candle and a jar of hydrogen – how would you prove experimentally that Hydrogen is a combustible gas.
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:
Iron [III] oxide to iron – using hydrogen.
Give reason for the following:
The reaction of chlorine with hydrogen sulphide is deemed a redox reaction.
Give a chemical test to distinguish between the following gases:
Hydrogen and oxygen
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.
Write down the “word equation” for the following reaction:
sodium hydroxide solution + zinc → ?
Complete and balance the following equations:
Al + NaOH + ____ → ____ + ____
Give balanced equation for obtaining hydrogen from cold water using a monovalent active metal.
Give balanced equation for obtaining hydrogen from cold water using a divalent active metal.
Select the correct answer from the symbol in the bracket.
The element, which like hydrogen has one valence electron.
