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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
Define ‘redox reaction’. Give one example.
The chemical formula for rust is.............. .
Identify the substances that are oxidised and the substances that are reduced in the following reaction.
\[\ce{4Na(s) + O2(g) -> 2Na2O(s)}\]
A shiny brown-coloured element ‘X’ on heating in air becomes black in colour. Name the element ‘X’ and the black-colored compound formed.
What is meant by rust?
Write the chemical formula of rust.
What are anti-oxidants?
Identify the component oxidised in the following reaction:
\[\ce{H2S + Cl2 -> S + 2HCl}\]
When a magnesium ribbon burns in air with a dazzling flame and forms a white ash, is magnesium oxidised or reduced? Why?
Is oxidation an exothermic or an endothermic reaction?
When a magnesium ribbon is heated, it burns in air to form magnesium oxide. Write a balanced chemical equation for this reaction. Name
- substance oxidised, and
- substance reduced.
In order to prevent the spoilage of potato chips, they are packed in plastic bags in an atmosphere of ______.
Fill in the blank
In redox reaction oxidation and reduction occur ............................
Define an oxidation reaction.
Define reduction.
Define redox reaction.
Explain the following in term Reduction of gain or loss of oxygen with two example.
Compare hydrogen with alkali metals on the basis of:
Oxide formation
In what respect does hydrogen differ from:
alkali metals
Give the general group study of hydrogen with reference to
reducing power
Why this reaction is considered a reversible reaction?
State whether the following conversion is oxidation or reduction:
PbO2 + SO2→ PbSO4
State whether the following conversion is oxidation or reduction:
Cu2+ + 2 e-→ Cu
State whether the following conversion is oxidation or reduction:
2Cl- - e-→ Cl2
For the reaction PbO + H2→ Pb + H2O, which of the following statements is wrong?
Name:
a substance that oxidizes concentrated HCl to chlorine.
Name:
a substance that will reduce aqueous Iron(III)ions to iron(II)ions.
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
Complete and balance the following equation:
Fe + H2O →___________+____________
State a reason why, when hydrogen is passed over heated copper oxide, the resultant product formed, differs in colour from the original reactant.
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.
Oxidising agents are also called as ______ because they remove electrons form other substances.
Oxidation is a process which 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.
Some bubbles of a gas are seen when lead (Pb) is reacted with the acid.
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.
Mention some oxidation reactions that occur in daily life.
Oxidizing agents are otherwise called ______.
The tarnishing of metals is an example of ______ reaction.
The sum of the oxidation number of all atoms in a compound is ______.
Choose the odd one out and write the reason:
Identify the following reactions as oxidation/reduction/redox reaction
Zn + CuSO4 → Cu + ZnSO4
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.
Ca in CaH2
Find the oxidation number of the element in the following compound.
A1 in AlCl3
In the redox reaction:
MnO2 + 4HCl → MnCl2 + 2H2O + Cl2
State whether the given chemical reaction is a redox reaction or not. Justify your answer.
\[\ce{MnO_2 + 4HCl->MnCl_2 +2H_2O + Cl_2}\]
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
Metals are good ______.
The metallic oxide which can be reduced by using common reducing agents is ______.
