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प्रश्न
Identify from the reaction the reactants that undergo oxidation and reduction.
2Mg + O2 → 2MgO
\[\ce{2Mg + O2 ->[\Delta] 2MgO}\]
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उत्तर १
In a reaction, magnesium is changing to magnesium oxide. That means, oxygen is being added to magnesium. Addition of oxygen to a substance is called oxidation, so magnesium undergoes oxidation.
उत्तर २
Mg undergoes oxidation and O2 undergoes reduction.
संबंधित प्रश्न
Define ‘redox reaction’. Give one example.
Identify the substances that are oxidised and the substances that are reduced in the following reaction.
\[\ce{4Na(s) + O2(g) -> 2Na2O(s)}\]
Explain the following in term Oxidation of gain or loss of oxygen with two example.
Is oxidation an exothermic or an endothermic reaction?
In the context of redox reactions, the removal of hydrogen from a substance is known as ______.
Identify the substances that are oxidised and the substances that are reduced in the following reaction.
\[\ce{CuO_{(s)} + H2_{(g)} -> Cu_{(s)} + H2O_{(l)}}\]
Electrolysis is a redox process. Explain.
Give scientific reason.
It is reccommended to use air tight container for storing oil for long time.
Is it essential that oxidation and reduction must occur side by side in a chemical reaction? Explain
State, giving reason, whether the substances printed in bold letters have been oxidized or reduced.
Mg + 2HCl → MgCl2 + H2
State, giving reason, whether the substances printed in bold letters have been oxidized or reduced.
H2S + Cl2→ 2HCl + S
State whether the following conversion is oxidation or reduction:
K → K+ + e-
Name:
an oxidizing agent that does not contain oxygen.
Name:
a substance that will reduce aqueous Iron(III)ions to iron(II)ions.
Name:
a liquid that is an oxidizing agent as well as a reducing agent.
Explain the term redox reaction with an example involving the reaction of hydrogen sulphide with chlorine.
Give two tests for a reducing agent.
When the positive charge on an ion increases or the negative charge on them decreases it is called as _______.
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\[\ce{MnO2 + 4HCl -> + 2H2O + Cl2}\]
Identify the substance oxidized in the above equation.
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 |
Identify the reducing agent in the following reactions -
`"H"_2"O" + "F"_2 -> "HF" + "HOF"`
Identify the reducing agent in the following reactions
`"Fe"_2"O"_3 + 3"CO" -> 2"Fe" + 3"CO"_2`
Identify the oxidising agent (oxidant) in the following reactions
`3"Fe" + 4"H"_2"O" -> "Fe"_3"O"_4 + 4"H"_2`
Which among the following are physical or chemical change?
Curding of milk
Zinc liberates hydrogen gas when reacted with dilute hydrochloric acid whereas copper does not. Explain why?
A silver article generally turns black when kept in the open for a few days. The article when rubbed with toothpaste again starts shining.
- Why do silver articles turn black when kept in the open for a few days? Name the phenomenon involved.
- Name the black substance formed and give its chemical formula.
What is a redox reaction?
The formation of brown colour on the freshly unit surface of vegetables and fruits is because ______ of organic compounds present in them.
The tarnishing of metals is an example of ______ reaction.
Identify the following reactions as oxidation/reduction/redox reaction
CuO+H2 → Cu+H2O
Find the oxidation number of the element in the following compound.
Ca in CaH2
It is recommended to use air tight containers for storing oil for a long time.
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
State the change in colour observed in following case mentioning the reason:
Copper powder is strongly heated in air.
Metals are good ______.
