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प्रश्न
State the change in colour observed in following case mentioning the reason:
Copper powder is strongly heated in air.
उत्तर
Copper powder turns from brown to black when heated vigorously in the presence of oxygen because oxygen reacts with copper powder to form copper oxide, which has a dark colour. Thus, the appearance of copper oxide is what causes the colour change.
\[\ce{2Cu(brown) +O2 ->2CuO(black)}\]
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संबंधित प्रश्न
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.
In the reaction represented by the equation:
MnO2 + 4HCl → MnCl2 + 2H2O + Cl2
(i) name the substance oxidised.
(ii) name the oxidising agent.
(iii) name the substance reduced.
(iv) name the reducing agent.
Define reduction.
The electron releasing tendency of zinc is ______ than that of copper.
Explain the following in term of gain or loss of oxygen with two examples.
Reduction
State whether the following conversion is oxidation or reduction:
K → K+ + e-
Divide the following reactions into oxidation and reduction half-reaction:
Zn + Pb2+→ Pb + Zn 2+
Name:
an oxidizing agent that does not contain oxygen.
Explain the term reduction in term of addition and removal of oxygen/hydrogen with a suitable example.
Give two tests for a reducing agent.
