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प्रश्न
Identify from the reaction the reactants that undergo oxidation and reduction.
\[\ce{NiO + H2 -> Ni + H2O}\]
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उत्तर
In a reaction, nickel oxide is changing to nickel. That is, oxygen is being removed from nickel oxide. Removal of oxygen from a substance is called reduction, so nickel oxide undergoes reduction.
In a reaction, hydrogen is changing to H2O. That is, oxygen is being added to hydrogen. Addition of oxygen to a substance is called oxidation, so hydrogen undergoes oxidation.
The reactions in which oxidation and reduction take place simultaneously are called Redox reactions.
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संबंधित प्रश्न
Why does the colour of copper sulphate solution change when an iron nail is dipped in it?
Identify the substances that are oxidised and the substances that are reduced in the following reaction.
\[\ce{4Na(s) + O2(g) -> 2Na2O(s)}\]
Which of the statements about the reaction below are incorrect?
\[\ce{2PbO(s) + C(s) → 2Pb(s) + CO2(g)}\]
- Lead is getting reduced.
- Carbon dioxide is getting oxidised.
- Carbon is getting oxidised.
- Lead oxide is getting reduced.
Write the chemical formula of rust.
Why is photosynthesis considered an endothermic reaction?
What are anti-oxidants?
Identify in the following reaction (a) the substance oxidised, and (b) the substance reduced:
\[\ce{ZnO + C -> Zn + CO}\]
The addition of oxygen to a substance is called ______ whereas removal of oxygen is called ______.
The addition of hydrogen to a substance is called ______ whereas removal of hydrogen is called ______.
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:
\[\ce{MnO2 + 4HCl -> MnCl2 + 2H2O + Cl2}\]
- name the substance oxidised.
- name the oxidising agent.
- name the substance reduced.
- name the reducing agent.
Is oxidation an exothermic or an endothermic reaction?
Give one example of an oxidation-reduction reaction which is also a displacement reaction.
In the context of redox reactions, the removal of hydrogen from a substance is known as ______.
The process of respiration is ______.
Fill in the blank
In redox reaction oxidation and reduction occur ............................
Define redox reaction.
MULTIPLE CHOICE QUESTIONS
The process of adding oxygen to a substance is called
- oxidation.
- reduction.
- displacement.
- hydrogenation.
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.
Reduction
In the following reaction: A+ + B → A + B+. Write half-reactions for this reaction and name:
- oxidizing agent
- substance oxidized
- reducing agent
Divide the following reactions into oxidation and reduction half-reaction:
Zn + Cu2+ → Cu + Zn 2+
Write the equation in the ionic form
CuSO4(aq) + Fe(s)→ FeSO4(aq) + Cu(s)
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:
an oxidizing agent that does not contain oxygen.
Name:
a liquid that is an oxidizing agent as well as a reducing agent.
With reference to oxidation & reduction reaction – complete the statement given by filling in the blanks with only the words (a) Addition (b) Removal.
‘Oxidation is a chemical reaction involving ____ of oxygen to a substance or ____ of hydrogen from a substance. Reduction on the otherhand involves ____ of hydrogen to a substance or ____ of oxygen from a substance.
State the condition and give balanced equation for the conversion of coke to water gas.
State what is oxidising agent. Give an example of oxidising agent in the gaseous, liquid, and solid form.
Give two test for an oxidising agent.
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+
Find the oxidation number of the elements in the following compounds.
- C in CO2
- Mn in MnSO4
- N in HNO3
\[\ce{MnO2 + 4HCl -> + 2H2O + Cl2}\]
Identify the substance oxidized in the above equation.
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
`"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"`
Identify the oxidising agent (oxidant) in the following reactions
`"CuSO"_4 + "Zn" -> "Cu" + "ZnSO"_4`
Identify the oxidising agent (oxidant) in the following reactions
`"V"_2"O"_5 + 5"Ca" -> 2"V" + 5"CaO"`
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?
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.
The reaction of sodium metal is found to be highly explosive
Explain this observation giving suitable reason.
Zinc liberates hydrogen gas when reacted with dilute hydrochloric acid whereas copper does not. Explain why?
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.
What is a redox reaction?
The sum of the oxidation number of all atoms in a compound is ______.
What are redox reactions? Give examples.
What is rancidity?
Find the oxidation number of the element in the following compound.
Mg in MgO
Find the oxidation number of the element in the following compound.
N in NH3
State whether the given chemical reaction is a redox reaction or not. Justify your answer.
\[\ce{MnO_2 + 4HCl->MnCl_2 +2H_2O + Cl_2}\]
