Advertisements
Advertisements
प्रश्न
What happens when zinc granules are treated with dilute solution of H2SO4, HCl, HNO3, NaCl and NaOH Also write the chemical equations if reaction oçcurs.
Advertisements
उत्तर
- With dilute H2SO4: Hydrogen gas evolves -
`"Zn"("s") + "H"_2"SO"_4 ("dil".) -> "ZnSO"_4("aq") + "H"_2("g")` - With dilute HCl: Hydrogen gas evolves -
`"Zn"("s") + 2"HCl" ("dil".) -> "ZnCl"_2("aq") + "H"_2("g")` - With dilute HNO3: Nitrous oxide gas evolves. It is colourless.
`4"Zn"("s") + 10"HNO"_3("aq") -> 4"Zn"("NO"_3)_2("aq") + 5"H"_2"O"("l") + "N"_2"O"("g")` - With NaCl : There is no chemical reaction, with NaOH : Hydrogen gas evolves:
`"Zn"("s") + 2"NaOH"("aq") -> underset("Sod. Zincare")("Na"_2"ZnO"_2("aq")) + "H"_2("g")` - NaOH solution
Zn(s) + 2 NaOH (aq) → Na2ZnO2(aq) + H2
APPEARS IN
संबंधित प्रश्न
Identify the substances that are oxidised and the substances that are reduced in the following reaction.
\[\ce{4Na(s) + O2(g) -> 2Na2O(s)}\]
Which of the statements about the reaction below are incorrect?
\[\ce{2PbO(s) + C(s) → 2Pb(s) + CO2(g)}\]
- Lead is getting reduced.
- Carbon dioxide is getting oxidised.
- Carbon is getting oxidised.
- Lead oxide is getting reduced.
Explain the following in term Oxidation of gain or loss of oxygen with two example.
When a magnesium ribbon is heated, it burns in air to form magnesium oxide. Write a balanced chemical equation for this reaction. Name
- substance oxidised, and
- substance reduced.
You are given the following chemical equation:
\[\ce{Mg_{(s)} + CuO_{(s)} -> MgO_{(s)} + Cu_{(s)}}\]
This equation represents:
Identify from the reaction the reactants that undergo oxidation and reduction.
2Mg + O2 → 2MgO
Explain the following in term of gain or loss of oxygen with two examples.
Oxidation
Divide the following reactions into oxidation and reduction half-reaction:
Zn + Pb2+→ Pb + Zn 2+
Name:
a substance that oxidizes concentrated HCl to chlorine.
Complete and balance the following equation:
H2 + S → ___________
Complete and balance the following equation:
Fe + H2O →___________+____________
Give two tests for a reducing agent.
The process of reduction involves ____________.
When Ag is exposed to air it gets a black coating of ____________.
In the reaction of iron with copper sulphate solution:
CuSO4 + Fe → Cu + FeSO4
Which option in the given table correctly represents the substance oxidized and the reducing agent?
| OPTION | Substance Oxidized | Reducing Agent |
| A | Fe | Fe |
| B | Fe | FeSO4 |
| C | Cu | Fe |
| D | CuSO4 | Fe |
During the reaction of some metals with dilute hydrochloric acid, following observations are made.
Some bubbles of a gas are seen when lead (Pb) is reacted with the acid.
Explain this observation giving suitable reason.
What is rancidity?
Metals are good ______.
The metallic oxide which can be reduced by using common reducing agents is ______.
