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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
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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
Write the chemical formula of rust.
Give an example of an oxidation reaction.
Identify the substances that are oxidised and the substances that are reduced in the following reaction.
\[\ce{CuO_{(s)} + H2_{(g)} -> Cu_{(s)} + H2O_{(l)}}\]
Identify from the reaction the reactants that undergo oxidation and reduction.
\[\ce{NiO + H2 -> Ni + H2O}\]
Name:
a substance that will reduce aqueous Iron(III)ions to iron(II)ions.
State what is oxidising agent. Give an example of oxidising agent in the gaseous, liquid, and solid form.
Give two test for an oxidising agent.
Identify the reducing agent in the following reactions -
`"H"_2"O" + "F"_2 -> "HF" + "HOF"`
During the reaction of some metals with dilute hydrochloric acid, following observations are made.
The reaction of sodium metal is found to be highly explosive
Explain this observation giving suitable reason.
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.
