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Oxidation and reduction

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Previous Bond features (Bond length,Bond energy and Bond angle)

Next Redox reactions

Previous Bond features (Bond length,Bond energy and Bond angle)

Next Redox reactions

Question#1

Which of the following is redox reaction [CBSE PMT 1997]

H₂SO₄ with NaOH

In atmosphere, O₃ from O₂ by lightning

Evaporation of H₂O

Nitrogen oxides form nitrogen and oxygen by lightning

Please select an option

Question#2

A Redox reaction

Metallic iron is a reducing agent

Fe³⁺ is an oxidising agent

Metallic iron is reduced to Fe³⁺

Please select an option

Question#3

When iron or zinc is added to CuSO₄ solution, copper is precipitated. It is due to [CPMT 1974, 79]

Oxidation of Cu⁺²

Reduction of Cu⁺²

Hydrolysis of CuSO₄

Ionization of CuSO₄

Please select an option

Question#4

Oxidation by 3 electrons

Reduction by 3 electrons

Oxidation by 5 electrons

Reduction by 5 electrons

Please select an option

Question#5

When Fe²⁺ changes to Fe³⁺ in a reaction

It loses an electron

It gains an electron

It loses a proton

It gains a proton

Please select an option

Question#6

Which halide is not oxidised by MnO₂ [MNR 1985; JIPMER 2000]

Please select an option

Question#7

Oxidation

Reduction

Neither oxidation nor reduction

Both oxidation and reduction

Please select an option

Question#8

Please select an option

Question#9

P is oxidized as well as reduced

P is reduced only

P is oxidised only

None of these

Please select an option

Question#10

Bromine is oxidised and carbonate is reduced

Bromine is reduced and water is oxidised

Bromine is neither reduced nor oxidised

Bromine is both reduced and oxidised

Please select an option

Question#11

Which one of the following reactions does not involve either oxidation or reduction [EAMCET 1982]

Please select an option

Question#12

In a reaction between zinc and iodine, in which zinc iodide is formed, what is being oxidised [NCERT 1975]

Zinc ions

Iodide ions

Zinc atom

Iodine

Please select an option

Question#13

Reduction involves [ NCERT 1972]

Loss of electrons

Gain of electrons

Increase in the valency of positive part

Decrease in the valency of negative part

Please select an option

Question#14

One gas bleaches the colour of flowers by reduction while the other by oxidation [EAMCET 1980]

CO and Cl₂

SO₂ and Cl₂

H₂S and Br₂

NH₃ and SO₂

Please select an option

Question#15

Oxidation

Reduction

Redox reaction

None of these

Please select an option

Question#16

Oxidation of thiosulphate ( S₂O₃^2- ) ion by iodine gives [NCERT 1976]

SO₃^2-

SO₄^2-

S₄O₆^2-

S₂O₆^2-

Please select an option

Question#17

When Sn²⁺ changes to Sn⁴⁺ in a reaction [CPMT 1981]

It loses two electrons

It gains two electrons

It loses two protons

It gains two protons

Please select an option

Question#18

Solution of sodium metal in liquid ammonia is strongly reducing due to the presence of the following in the solution [NCERT 1977; KCET (Med.) 2000]

Sodium atoms

Solvated electrons

Sodium hydride

Sodium amide

Please select an option

Question#19

When copper turnings are added to silver nitrate solution, a blue-coloured solution is formed after some time. It is because, copper [CPMT 1974, 79; DPMT 2000]

Displaces silver from the solution

Forms a blue coloured complex with AgNO₃

Is oxidised to Cu²⁺

Is reduced to Cu²⁺

Please select an option

Question#20

Incorrect statement regarding rusting is [MP PET 2000]

Metallic iron is oxidised to Fe³⁺ ions

Metallic iron is reduced to Fe^2- ions

Oxygen gas is reduced to oxide ion

Yellowish – brown product is formed

Please select an option

Question#21

Oxidation involves [NCERT 1971, 81; CPMT 1980, 82, 83; MP PMT 1983]

Loss of electrons

Gain of electrons

Increase in the valency of negative part

Decrease in the valency of positive part

Please select an option

Question#22

SnCl₂ gives a precipitate with a solution of . HgCl₂ In this process HgCl₂ is [CPMT 1983]

Reduced

Oxidised

Converted into a complex compound containing both Sn and Hg

Converted into a chloro complex of Hg

Please select an option

Question#23

This is an example of a redox reaction

Metallic iron is reduced to Fe³⁺

Fe³⁺ is an oxidising agent

Metallic iron is a reducing agent

Please select an option

Question#24

When sodium metal is dissolved in liquid ammonia, blue colour solution is formed. The blue colour is due to [NCERT 1981]

Solvated Na⁺ ions

Solvated electrons

Solvated NH₂^_ ions

Solvated protons

Please select an option

Question#25

Magnesium is reduced

Magnesium is oxidized

Nitrogen is oxidized

None of these

Please select an option

Question#26

Max. number of moles of electrons taken up by one mole of NO₃^_ when it is reduced to [DPMT 2002]

NH₃

NH₂OH

NO₂

Please select an option

Question#27

H₂O₂ reduces K₄Fe(CN)₆ [MP PMT 1985]

In neutral solution

In acidic solution

In non-polar solvent

In alkaline solution

Please select an option

Question#28

H₂S reacts with halogens, the halogens [JIPMER 2000]

Form sulphur halides

Are oxidised

Are reduced

None of these

Please select an option

Question#29

Redox

Neutralisation

Oxidation

Reduction

Please select an option

Question#30

In the course of a chemical reaction an oxidant [MP PMT 1986]

Loses electrons

Gains electrons

Both loses and gains electron

Electron change takes place

Please select an option

Question#31

The conversion of PbO₂ to Pb(NO₃)₂ is

Oxidation

Reduction

Neither oxidation nor reduction

Both oxidation and reduction

Please select an option

Question#32

Oxidised

Reduced

Precipitated

None of these

Please select an option

Question#33

Which one of the following does not get oxidised by bromine water [MP PET/PM 2001]

Fe⁺² to Fe⁺³

Cu⁺ to Cu⁺²

Mn⁺² to MnO₄^_

Sn⁺² to Sn⁺⁴

Please select an option

Question#34

When P reacts with caustic soda, the products are PH₃ and . NaH₂PO₂ This reaction is an example of [IIT 1980; Kurukshetra CEE 1993; CPMT 1997]

Oxidation

Reduction

Oxidation and reduction (Redox)

Neutralization

Please select an option

Question#35

The ultimate products of oxidation of most of hydrogen and carbon in food stuffs are [DCE 2001]

H₂O alone

CO₂ alone

H₂O and CO₂

None of these

Please select an option

Question#36

When a sulphur atom becomes a sulphide ion [AMU 1999]

There is no change in the composition of atom

It gains two electrons

The mass number changes

None of these

Please select an option

Question#37

H₂O₂ reduces MnO₄^- ion to [KCET (Med.) 2000]

Mn⁺

Mn²⁺

Mn³⁺

Mn^_

Please select an option

Question#38

The oxidation number of carbon in Mg(HCO₃)₂? ; (2018-ETEA)

-4

-2

ZERO

Please select an option

Question#39

Oxidation number of an element in free state is NUMS2021

-1

Please select an option

Question#40

Reductions occurs at NUMS2021

Anode

Cathode

Salt bridge

None of the these options are correct

Please select an option

Question#41

In which of following, oxygen shows fractional oxidation number MDCAT-2022

OF2

Na2O2

KO2

Cl2O7

Please select an option

Question#42

The common oxidation number of halogens is MDCAT2020

-1

-2

Please select an option

Question#43

The oxidation state of ''S'' in the \( S_2O_3^{-2} \) is: MDCAT2020

-2

Please select an option

Question#44

The oxidation state of nitrogen in NH₄NO₃are ETEA2019

-3 and 5

+5 and 3

-3 and +3

Zero

Please select an option

Question#45

Rusting of Iron metal occurs when Fe gets converted into Fe₂O₃. What happened with Fe? SET2019

Fe is neutralized

Fe is sublimed

Fe is reduced

Fe is oxidized

Please select an option

Question#46

In all oxidation reaction, atoms of an element in a chemical specie lose electrons and increases their MDCAT2011 MDCAT2020

Oxidation state

Electrons

Electrode

Negative charge

Please select an option

Question#47

In MgCl2 the oxidation state of Cl is MDCAT2012

Zero

-2

-1

Please select an option

Question#48

In SO₄^-2 the oxidation number of Sulphur is MDCAT2016

-8

-6

Please select an option

Question#49

The value of oxidation number of Cl in HClO₃ is SET2019

-1

Please select an option

Question#50

The oxidation state of carbon in C₂O₄^-2 is NUMS2019

-4

Please select an option

Question#51

In NO₃^-1 the oxidation number of N is MDCAT2017

-3

Please select an option

Related MCQ's Catrgories

Oxidation and reduction

Redox reactions

Method for balancing redox reaction

Electrolytes and Electrolysis

Voltaic Cell / Galvanic cell

Electrode Potential

Electrochemical series(ECS) and Applications Of ECS

Oxidizing and Reducing agent

Faraday's law of electrolysis

Standard hydrogen electrode

Oxidation number and Oxidation state

Home/Electrochemistry Oxidation and reduction

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Oxidation and reduction