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Question
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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Solution
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.
RELATED QUESTIONS
Match the statements in Column A with those in Column B.
| Column A | Column B |
|
1. A metal which reacts with cold water to from hydrogen. |
1. Reduction |
| 2. A gas which is inflammable and non-supporter of combustion | 2. Hydrogenation |
|
3. A process in which vanspati ghee is prepared from vegitable oils |
3. oxidation |
|
4. The removal ofhydrogen or addition of oxygen |
4. sodium |
| 5. The addition of hydrogen or removal of oxygen | 5. 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?
Complete and balance the following reaction.
Ca + H2O →_____________ +___________
Complete and balance the following reaction.
Mg + H2O →_____________ +___________
Complete and balance the following reaction.
Al + KOH + H2O→_____________ +___________
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Answer the following pertaining to the preparation of hydrogen by electrolysis,
The meaning of the term ‘electrolysis’ and ‘electrolyte’.
Select the correct options for the following statement:
The acid _____ is not Used in the laboratory preparation of hydrogen, using zinc and an acid.
Complete and balance the equation:
[General method]
Reactions of metals with dilute acids
Aluminium - 2Al + 3H2SO4 → ______+ _______ [g]
Give a balanced equation for the following conversion.
\[\ce{MgCl2<-HCl->FeCl2}\]
Give a balanced equation for the following conversion.
\[\ce{NH3<-H2->H2S}\]
