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प्रश्न
Hydrogen can be prepared with the help of cold water. Give a reaction of hydrogen with:
A divalent metal
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उत्तर
Ca + 2H2O → Ca(OH)2 + H2
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संबंधित प्रश्न
Hydrogen gas is collected by the downward displacement of water. Give reason ?
Why hot concentrated sulphuric acid is not used in the preparation of hydrogen?
Give reason for the following:
Dilute sulphuric acid cannot be replaced by concentrated acid in the preparation of hydrogen.
Hydrogen may be prepared in the laboratory by the action of a metal on an acid.
How would you modify your apparatus to collect dry hydrogen? Which drying agent would you employ for this purpose?
‘Hydrogen is obtained by electrolysis of acidified water’.
Answer the following pertaining to the preparation of hydrogen by electrolysis,
Name the electrode –
- through which the current enters the electrolyte.
- at which hydrogen is liberated.
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 - alkali [conc. soln.]
Lead - Pb + 2NaOH → ______ + _______ [g]
Name an element whsich reacts violently with water at room temperature.
State why hydrogen is not prepared in the laboratory by the action of sodium with cold water.
Select the correct answer to the reactant added, to give the product in the preparation of hydrogen gas.
\[\ce{NaAlO2 + H2}\]
