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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
Explain the following in term Oxidation of gain or loss of oxygen with two example.
Write the chemical formula of rust.
What are anti-oxidants? Why are they added to fat and oil containing foods?
What is an oxidation reaction? Identify in the following reaction (i) the substance oxidised, and (ii) the substance reduced:
ZnO + C → Zn + CO
When a magnesium ribbon burns in air with a dazzling flame and forms a white ash, is magnesium oxidised or reduced? Why?
In the reaction represented by the equation:
MnO2 + 4HCl → MnCl2 + 2H2O + Cl2
(i) name the substance oxidised.
(ii) name the oxidising agent.
(iii) name the substance reduced.
(iv) name the reducing agent.
Give one example of an oxidation-reduction reaction which is also a combination reaction.
In the reaction represented by the following equation:
CuO (s) + H2 (g) → Cu (s) + H2O (1)
(a) name the substance oxidised
(b) name the substance reduced
(c) name the oxidising agent
(d) name the reducing agent
In the context of redox reactions, the removal of hydrogen from a substance is known as:
(a) oxidation
(b) dehydration
(c) reduction
(d) dehydrogenation
You are given the following chemical equation:
Mg (s) + CuO (s) → MgO (s) + Cu (s)
This equation represents:
(a) decomposition reaction as well as displacement reaction
(b) combination reaction as well as double displacement reaction
(c) redox reaction as well as displacement reaction
(d) double displacement reaction as well as redox reaction
Hydrogen burns with a ______ flame and ______ sound is heard.
Indicate which of the following statement is true and which is false:
The removal of hydrogen from a substance is called reduction.
Define reduction.
MULTIPLE CHOICE QUESTIONS
The process of adding oxygen to a substance is called
- oxidation.
- reduction.
- displacement.
- hydrogenation.
TRUE \ FALSE
Hydrogen is a good oxidizing agent.
Identify the substances that are oxidised and the substances that are reduced in the following reaction.
\[\ce{CuO_{(s)} + H2_{(g)} -> Cu_{(s)} + H2O_{(l)}}\]
Explain the following in term Reduction of gain or loss of oxygen with two example.
The electron releasing tendency of zinc is ______ than that of copper.
How would you change a metal like Cu into its ions?
Explain the following in term of gain or loss of oxygen with two examples.
Reduction
Why zinc and aluminium are considered to have a unique nature. Give balanced equations to support your answer.
Describe briefly the ionic concept of oxidation and reduction. Give an equation to illustrate.
State whether the following conversion is oxidation or reduction:
PbO2 + SO2→ PbSO4
Write the equation in the ionic form
CuSO4(aq) + Fe(s)→ FeSO4(aq) + Cu(s)
Divide the above equation into oxidation and reduction half-reactions.
Name:
an oxidizing agent that does not contain oxygen.
Name:
a gas that is oxidizing as well as a reducing agent.
Name:
a solid that is an oxidizing agent.
Complete and balance the following equation:
H2 + S → ___________
Oxidising agents are also called as ______ because they remove electrons form other substances.
Find the oxidation number of the elements in the following compounds.
- C in CO2
- Mn in MnSO4
- N in HNO3
Rusting of iron involves a chemical reaction which is a combination of:
Oxidation is a process which involves ____________.
The process of reduction involves ____________.
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 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?
Evaporation of petrol
Which among the following are physical or chemical change?
Burning of Liquefied Petroleum Gas (LPG)
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.
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.
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?
Write a short note on oxidizing and reducing agents.
Mention some oxidation reactions that occur in daily life.
The tarnishing of metals is due to the formation of ______.
______ is a metal that has a high resistance to corrosion.
Identify the following reactions as oxidation/reduction/redox reaction
2Mg +O2 → 2MgO
What are reducing agents? 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.
A1 in AlCl3
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.
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.
