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प्रश्न
Identify from the reaction the reactants that undergo oxidation and reduction.
Fe + S → FeS
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उत्तर १
Fe + S → FeS
In a reaction, Fe is changing to FeS. That means, iron loses electrons to form FeS. Loss of electron from a substance is called oxidation, so iron undergoes oxidation.
उत्तर २
Iron (Fe) undergoes oxidation and Sulphur (S) undergoes reduction.
संबंधित प्रश्न
Corrosion can be prevented by using ……………. solution.
What is an oxidising agent?
Identify the substances that are oxidised and the substances that are reduced in the following reaction.
\[\ce{4Na(s) + O2(g) -> 2Na2O(s)}\]
What is meant by rust?
Write the chemical formula of rust.
Identify in the following reaction (a) the substance oxidised, and (b) the substance reduced:
\[\ce{ZnO + C -> Zn + CO}\]
When SO2 gas is passed through saturated solution of H2S, the following reaction occurs:
\[\ce{SO2 + 2H2S -> 2H2O + 3S}\]
In this reaction, which substance is oxidised and which one is reduced?
The addition of hydrogen to a substance is called ______ whereas removal of hydrogen is called ______.
Define the following in terms of gain or loss of hydrogen with one example:
Oxidation
In the context of redox reactions, the removal of hydrogen from a substance is known as ______.
Hydrogen burns with a ______ flame and ______ sound is heard.
Fill in the blank
Oxidation is the removal of ......................and addition of ....................
Define an oxidation reaction.
Define reduction.
TRUE \ FALSE
Hydrogen is a good oxidizing agent.
Explain the following in term Reduction of gain or loss of oxygen with two example.
Identify from the reaction the reactants that undergo oxidation and reduction.
2Mg + O2 → 2MgO
In what respect does hydrogen differ from:
alkali metals
Why this reaction is considered a reversible reaction?
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.
PbO + CO → Pb + CO2
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
Divide the following reactions into oxidation and reduction half-reaction:
Zn + Cu2+ → Cu + Zn 2+
Which of the following statements about hydrogen is incorrect?
Choose terms from the options given in brackets to complete this sentence.
When CuO reacts with hydrogen,………………… is reduced and ……………….is oxidized to ………………….
(CuO, H2, Cu, H2O)
Name:
a substance that oxidizes concentrated HCl to chlorine.
Name:
a gas that is oxidizing as well as a reducing agent.
Complete and balance the following equation:
Fe + H2O →___________+____________
Explain the term redox reaction with an example involving the reaction of hydrogen sulphide with chlorine.
\[\ce{MnO2 + 4HCl -> + 2H2O + Cl2}\]
Identify the substance oxidized in the above equation.
When Ag is exposed to air it gets a black coating of ____________.
Select the oxidising agent for the following reaction:
\[\ce{H2S + I2 -> 2HI + S}\]
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
`4"NH"_3 + 5"O"_2 -> 4"NO" + 6"H"_2"O"`
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
`2"Mg" + "O"_2 -> 2"MgO"`
Identify the oxidising agent (oxidant) in the following reactions
`3"Fe" + 4"H"_2"O" -> "Fe"_3"O"_4 + 4"H"_2`
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.
Oxidizing agents are otherwise called ______.
______ is a metal that has a high resistance to corrosion.
Define oxidation number.
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
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.
In the redox reaction:
MnO2 + 4HCl → MnCl2 + 2H2O + Cl2
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
