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प्रश्न
A reddish brown metal used in electrical wires when powdered and heated strongly turns black. When hydrogen gas is passed over this black substance, it regains its original colour. Based on this information answer the following questions:
- Name the metal and the black substance formed.
- Write balanced chemical equations for the two reactions involved in the above information
उत्तर
- The metal is called copper (Cu), and the black substance generated is called copper oxide.
- The balanced chemical reactions for both the reactions are as follows:
When powdered copper is heated strongly in the presence of oxygen copper oxide is.
\[\ce{2Cu(s) + O_2(g) ->[\Delta]2CuO(s)}\]
When hydrogen gas is passed over copper oxide, it produces copper metal and water.
\[\ce{CuO(s) + H_2(g) ->Cu(s) + H_2O(l)}\]
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संबंधित प्रश्न
Define ‘redox reaction’. Give one example.
What are anti-oxidants? Why are they added to fat and oil containing foods?
Identify the substances that are oxidised and the substances that are reduced in the following reaction.
\[\ce{CuO(s) + H2(g) -> Cu(s) + H2O (l)}\]
State, giving reason, whether the substances printed in bold letters have been oxidized or reduced.
Cl2 + H2S → 2HCl + S
In the following reaction: A+ + B → A + B+. Write half-reactions for this reaction and name:
- oxidizing agent
- substance oxidized
- reducing agent
Name:
a substance that will reduce aqueous Iron(III)ions to iron(II)ions.
Which of the following statements about the given reaction are correct?
\[\ce{3Fe_{(s)} + 4H2O_{(g)} -> Fe3O4_{(s)} + 4H2_{(g)}}\]
(i) Iron metal is getting oxidised.
(ii) Water is getting reduced.
(iii) Water is acting as the reducing agent.
(iv) Water is acting as oxidising agent.
The process of reduction involves ____________.
Identify the following reactions as oxidation/reduction/redox reaction
Zn + CuSO4 → Cu + ZnSO4
Define oxidation number.
