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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
Define ‘redox reaction’. Give one example.
A shiny brown-coloured element ‘X’ on heating in air becomes black in colour. Name the element ‘X’ and the black-colored compound formed.
Write the chemical formula of rust.
What are anti-oxidants? Why are they added to fat and oil containing foods?
In the following reaction between lead sulphide and hydrogen peroxide:
PbS (s) + 4H2O2(aq) → PbSO4(s) + 4H2O(1)
(a) which substance is reduced?
(b) Which substance is oxidised?
Give one example of an oxidation-reduction reaction which is also a displacement reaction.
Explain oxidation in terms of gain or loss of oxygen with one example.
Define oxidation in terms of gain or loss of hydrogen with one example.
In the context of redox reactions, the removal of hydrogen from a substance is known as:
(a) oxidation
(b) dehydration
(c) reduction
(d) dehydrogenation
Fill in the blank
In redox reaction oxidation and reduction occur ............................
Indicate which of the following statement is true and which is false:
The removal of hydrogen from a substance is called reduction.
Define an oxidation reaction.
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.
Electrolysis is a redox process. Explain.
Identify from the following reaction the reactants that undergo oxidation and reduction.
\[\ce{2Ag2O → 4 Ag + O2 \uparrow}\]
Compare hydrogen and halogens on the basis of:
reaction with oxygen
Why this reaction is considered a reversible reaction?
Divide the following reactions into oxidation and reduction half-reaction:
Zn + Pb2+→ Pb + Zn 2+
Divide the above equation into oxidation and reduction half-reactions.
Reacting with water, an active metal produces
Name:
a liquid that is an oxidizing agent as well as a reducing agent.
Name:
a solid that is an oxidizing agent.
Complete and balance the following equation:
Zn +_________________→ZnCl2 + H2
State a reason why, when hydrogen is passed over heated copper oxide, the resultant product formed, differs in colour from the original reactant.
State the condition and give balanced equation for the conversion of coke to water gas.
Explain the term oxidation in term of addition and removal of oxygen/hydrogen with a suitable example.
Explain the term reduction in term of addition and removal of oxygen/hydrogen with a suitable example.
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 _______.
Explain the following reaction with their balanced chemical equation.
Hydrogen sulphide reacts with sulphur dioxide.
Balance the given chemical reaction as per the instructions below.
\[\ce{NaOH + H2SO4 -> Na2SO4 + H2O}\]
Oxidation means losing electrons then what is reduction?
Identify the following reactions as oxidation or reduction
- Na → Na+ + e
- Fe3+ + 2 e- → Fe+
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 -
`"H"_2"O" + "F"_2 -> "HF" + "HOF"`
Identify the oxidising agent (oxidant) in the following reactions.
`"CuO" + "H"_2 -> "Cu" + "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
Which among the following are physical or chemical change?
Sublimation of solid ammonium chloride
During the reaction of some metals with dilute hydrochloric acid, following observations are made.
Silver metal does not show any change
Explain this observation giving suitable reason.
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?
The tendency of atoms to have eight electrons in the outer shell is known as ______.
The tarnishing of metals is due to the formation of ______.
The sum of the oxidation number of all atoms in a compound is ______.
______ is a metal that has a high resistance to corrosion.
Identify the following reactions as oxidation/reduction/redox reaction
2Mg +O2 → 2MgO
Find the oxidation number of the element in the following compound.
Ca in CaH2
Find the oxidation number of the element in the following compound.
N in NH3
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).
