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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.
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संबंधित प्रश्न
Define corrosion.
Identify in the following reaction (a) the substance oxidised, and (b) the substance reduced:
\[\ce{ZnO + C -> Zn + CO}\]
The addition of hydrogen to a substance is called ______ whereas removal of hydrogen is called ______.
Explain the following in terms of gain or loss of oxygen with one example:
Oxidation
Explain the following in terms of gain or loss of oxygen with one example:
Reduction
Define the following in terms of gain or loss of hydrogen with one example:
Oxidation
You are given the following chemical equation:
\[\ce{Mg_{(s)} + CuO_{(s)} -> MgO_{(s)} + Cu_{(s)}}\]
This equation represents:
Define an oxidation reaction.
Define reduction.
Define redox reaction.
The colours of aqueous solutions of CuSO4 and FeSO4 as observed in the laboratory are:
(A) pale green and light blue respectively
(B) light blue and dark green respectively
(C) dark blue and dark green respectively
(D) dark blue and pale green respectively
Give scientific reason.
It is reccommended to use air tight container for storing oil for long time.
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
Explain the following in term of gain or loss of oxygen with two examples.
Oxidation
Give the general group study of hydrogen with reference to
burning
Give the general group study of hydrogen with reference to
reducing power
State, giving reason, whether the substances printed in bold letters have been oxidized or reduced.
Mg + 2HCl → MgCl2 + H2
State whether the following conversion is oxidation or reduction:
Cu2+ + 2 e-→ Cu
State whether the following conversion is oxidation or reduction:
K → K+ + e-
For the reaction PbO + H2→ Pb + H2O, which of the following statements is wrong?
Name:
a solid that is an oxidizing agent.
Complete and balance the following equation:
\[\ce{K + H2O -> }\]________+ ________
Complete and balance the following equation:
Fe + H2O →___________+____________
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.
Select the correct answer from the symbol in the bracket.
The element, which like hydrogen is a strong reducing agent.
When the positive charge on an ion increases or the negative charge on them decreases it is called as _______.
Oxidising agents are also called as ______ because they remove electrons form other substances.
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 ____________.
Select the oxidising agent for the following reaction:
\[\ce{H2S + I2 -> 2HI + S}\]
Grapes hanging on the plant do not ferment but after being plucked from the plant can be fermented. Under what conditions do these grapes ferment? Is it a chemical or a physical change?
During the reaction of some metals with dilute hydrochloric acid, following observations are made.
The temperature of the reaction mixture rises when aluminium (Al) is added.
Explain this observation giving suitable reason.
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 are reducing agents? Give examples.
What are redox reactions? Give examples.
Find the oxidation number of the element in the following compound.
Zn in ZnSO4
Find the oxidation number of the element in the following compound.
N in NH3
Find the oxidation number of the element in the following compound.
A1 in AlCl3
Identify the type of chemical reaction given below:
\[\ce{2Mg + O2 -> 2MgO}\]
When hydrogen gas is passed over black copper oxide, a reddish-coloured layer of copper is formed.
Answer the questions that follow based on this reaction.
- Write the equation.
- What type of reaction is it?
- Complete the blanks:
In this reaction, an oxygen atom goes away from CuO (copper oxide), which means that ______ of copper oxide takes place, whereas a hydrogen molecule takes up an oxygen atom and water (H2O) is formed, meaning ______ of hydrogen takes place.
It is recommended to use air tight containers for storing oil for a long time.
State the change in colour observed in following case mentioning the reason:
Copper powder is strongly heated in air.
The oxidizing agent in the equation \[\ce{S + 2H2SO4 -> 3SO2 + 2H2O}\] is ______.
