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प्रश्न
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.
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उत्तर
Dilute sulphuric acid.
Conc. nitric acid, even in its diluted form, is not used in the preparation of hydrogen from metals because it is a powerful oxidising agent and oxygen formed due to its decomposition oxidises hydrogen to give water, thus defeating the purpose of the reaction.
Conc. sulphuric acid is not used in the preparation of hydrogen as it will produce sulphur dioxide.
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संबंधित प्रश्न
For laboratory preparation of hydrogen, give the following:
materials used
Why hot concentrated sulphuric acid is not used in the preparation of hydrogen?
Hydrogen can be prepared with the help of cold water. Give a reaction of hydrogen with:
A divalent metal
Complete and balance the following reaction.
Ca + H2O →_____________ +___________
Complete and balance the following reaction.
Zn + NaOH →_____________ +___________
State how hydrogen occurs in the free state. Name three compounds containing hydrogen in the combined state.
Give reason for the following:
In the preparation of hydrogen by electrolysis of water – the distilled water used is acidified.
Select the correct options for the following statement:
The product formed on combustion of hydrogen in air is ___.
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.
State the reactant added to hydrogen to obtain the respective product in following case.
Hydrogen sulphide
