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प्रश्न
Account for the following fact:
Though lead is above hydrogen in the activity series, it does not react with dilute hydrochloric acid or dilutes sulphuric acid.
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उत्तर
Pb (lead) is above hydrogen in reactivity series. With dil. HCl, Pb forms PbCl2 and with dil. H2SO4, Pb forms PbSO4 both PbCl2 and PbSO4 are insoluble and forms a respective coating to stop the further reaction.
संबंधित प्रश्न
FILL IN THE BLANK
In electrolysis of water, dilute sulphuric acid is added to increase ..................of water.
Why hot concentrated sulphuric acid is not used in the preparation of hydrogen?
Choose the correct option:
Elements which show unique nature in the preparation of hydrogen are:
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.
Why are the following metals not used in the lab preparation of hydrogen?
calcium
Complete and balance the following reaction.
Na + H2O →_____________ +___________
Complete and balance the following reaction.
Fe + HCl →_____________ +___________
Complete and balance the following reaction.
Zn + NaOH →_____________ +___________
‘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.
Select the correct options for the following statement:
The metallic compound formed when a metal above aluminium in the activity series reacts with steam.
