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प्रश्न
Define ‘redox reaction’. Give one example.
What is redox reaction? Explain with one example
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उत्तर १
When oxidation and reduction occur simultaneously in a given chemical reaction, it is known as a redox reaction.
Example of a redox reaction:
Reduction Oxidation
BaSO4 +4C → BaS+4CO
उत्तर २
The reaction in which simultaneous oxidation and reduction take place is called a redox reaction
Cu+2 + Zn → Zn+2 + Cu
in the above reaction, copper undergoes reduction whereas Zn undergoes oxidation.
Therefore the reaction is redox reaction.
उत्तर ३
The reaction in which one substance gets oxidised and other gets reduced is known as redox reaction.
Example:
ZnO + C → Zn + CO
Here, C is oxidised to CO because oxygen is being added and ZnO is reduced to Zn because oxygen is being removed. Therefore, it is a redox reaction.
संबंधित प्रश्न
Corrosion can be prevented by using ……………. solution.
Define corrosion.
Write the chemical formula of rust.
Why is photosynthesis considered an endothermic reaction?
What are anti-oxidants? Why are they added to fat and oil containing foods?
Fill in the following blanks with suitable words:
The addition of oxygen to a substance is called ......... whereas removal of oxygen is called ........
Fill in the following blanks with suitable words:
The addition of hydrogen to a substance is called ........ whereas removal of hydrogen is called .......
Is oxidation an exothermic or an endothermic reaction?
Give one example of an oxidation-reduction reaction which is also a displacement reaction.
Explain reduction in terms of gain or loss of oxygen with one example.
When copper powder is heated strongly in air, it forms copper oxide. Write a balanced chemical equation for this reaction. Name (i) substance oxidised, and (ii) substance reduced.
Define oxidation in terms of gain or loss of hydrogen with one example.
When a magnesium ribbon is heated, it burns in air to form magnesium oxide. Write a balanced chemical equation for this reaction. Name (i) substance oxidised, and (ii) substance reduced.
In order to prevent the spoilage of potato chips, they are packed in plastic bags in an atmosphere of:
(a) Cl2
(b) H2
(c) N2
(d) O2
Fill in the blank
In redox reaction oxidation and reduction occur ............................
Define an oxidation reaction.
Define reduction.
MULTIPLE CHOICE QUESTIONS
The process of adding oxygen to a substance is called
- oxidation.
- reduction.
- displacement.
- hydrogenation.
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.
Fe + S → FeS
Identify from the following reaction the reactants that undergo oxidation and reduction.
\[\ce{2Ag2O → 4 Ag + O2 \uparrow}\]
Identify from the reaction the reactants that undergo oxidation and reduction.
2Mg + O2 → 2MgO
Compare hydrogen with alkali metals on the basis of:
Oxide formation
Give the general group study of hydrogen with reference to
reducing power
Compare hydrogen and halogens on the basis of:
reaction with oxygen
State, giving reason, whether the substances printed in bold letters have been oxidized or reduced.
PbO + CO → Pb + CO2
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:
PbO2 + SO2→ PbSO4
State whether the following conversion is oxidation or reduction:
Cu2+ + 2 e-→ Cu
Divide the following reactions into oxidation and reduction half-reaction:
Zn + Pb2+→ Pb + Zn 2+
Divide the following reactions into oxidation and reduction half-reaction:
Cl2 + 2Br- → Br2 + 2Cl-
Divide the above equation into oxidation and reduction half-reactions.
A metal oxide that is reduced by hydrogen is
Which of the following statements about hydrogen is incorrect?
Name:
a liquid that is an oxidizing agent as well as a reducing agent.
Complete and balance the following equation:
CuO +__________→ Cu +___________
Explain the term redox reaction with an example involving the reaction of hydrogen sulphide with chlorine.
State what is oxidising agent. Give an example of oxidising agent in the gaseous, liquid, and solid form.
State what is reducing agent. Give an example of oxidising agent in the gaseous, liquid, and solid form.
Rusting of iron involves a chemical reaction which is a combination of:
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 reducing agent in the following reactions
`"Fe"_2"O"_3 + 3"CO" -> 2"Fe" + 3"CO"_2`
Identify the reducing agent in the following reactions
`2"H"_2 + "O"_2 -> 2"H"_2"O"`
Identify the oxidising agent (oxidant) in the following reactions
`"Pb"_3"O"_4 + 8"HCl" -> 3"PbCl"_2 + "Cl"_2 + 4"H"_2"O"`
Which among the following are physical or chemical change?
Burning of Liquefied Petroleum Gas (LPG)
Which among the following are physical or chemical change?
Heating of an iron rod to red hot
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.
Why do we store silver chloride in a dark coloured bottle?
Zinc liberates hydrogen gas when reacted with dilute hydrochloric acid whereas copper does not. Explain why?
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.
On adding a drop of barium chloride solution to an aqueous solution of sodium sulphite, white precipitate is obtained :
- Write a balanced chemical equation for the reaction involved.
- What other name can be given to this precipitation reaction?
- On adding dilute hydrochloric acid to the reaction mixture, white precipitate disappears. Why?
You are provided with two containers made up of copper and aluminium. You are also provided with solutions of dilute HCl, dilute HNO3, ZnCl2 and water. In which of the above containers, can these solutions be kept?
What is a redox reaction?
Mention some oxidation reactions that occur in daily life.
______ is a metal that has a high resistance to corrosion.
Choose the odd one out and write the reason:
Identify the following reactions as oxidation/reduction/redox reaction
2Mg +O2 → 2MgO
What are reducing agents? Give examples.
Define oxidation number.
Find the oxidation number of the element in the following compound.
Mg in MgO
Identify the type of chemical reaction given below:
\[\ce{2Mg + O2 -> 2MgO}\]
Answer the questions based on the equation below:
\[\ce{CH3 - CH2 - OH ->[{[O]}][K2Cr2O7/H2SO4] CH3 - COOH}\]
- What type of reaction is it?
- What is the role of the chemical written on the arrow?
- Give one example of one such type of chemical as in answer (b).
In the redox reaction:
MnO2 + 4HCl → MnCl2 + 2H2O + Cl2
The oxidizing agent in the equation \[\ce{S + 2H2SO4 -> 3SO2 + 2H2O}\] is ______.
