2 : What change in oxidation state takes place in nitrogen when copper reacts with HNO3 according to the equation? Cu + HNO3 → Cu(NO2) + NO2 + H2O
1 : +5 to -2
2 : +5 to +4
3 : +5 to 0
4 : 0 to -4
3 : Oxidation number of oxygen in OF2 is:
1 : Zero
2 : -1/2
3 : +2
4 : -1
4 : In H2O2, the oxidation state of oxygen is:
1 : +1
2 : -1
3 : +2
4 : 3
5 : Oxidation number of an element in free state is:
1 : Zero
2 : 1
3 : 2
4 : 3
6 : An oxidizing agent:
1 : Loses Electron
2 : Is oxidized
3 : Neither gains nor loses electrons
4 : Gains Electrons
7 : Oxidation number of chromium in Cr2O7-2 is:
1 : +3
2 : +4
3 : +5
4 : +6
8 : According to classical concept, oxidation involves:
1 : Addition of oxygen
2 : removal of oxygen
3 : increase in oxidation state
4 : all of above
9 : Sulphur has highest oxidation state in:
1 : SO3
2 : SO2
3 : H2S
4 : H2SO3
10 : Oxidation state in Mn in MnO4-2 is:
1 : +4
2 : +6
3 : +5
4 : -6
11 : Loss of electrons is called:
1 : oxidation
2 : reduction
3 : hydration
4 : dehydration
12 : In Na2O2, the oxidation state of oxygen is:
1 : -2
2 : +2
3 : -1
4 : +1
13 : In H2SO4, the oxidation number of S is:
1 : +2
2 : +6
3 : +8
4 : +4
14 : Oxidation number of oxygen in H2O is:
1 : -2
2 : -1
3 : +1
4 : zero
15 : The oxidation state of Cl in Ca(ClO3)2 is:
1 : -1
2 : +5
3 : +3
4 : +1
16 : The oxidation state of Cl in HClO4 is:
1 : +2
2 : +3
3 : +5
4 : +7
17 : In which of the following the oxidation number of Cr is not +6:
1 : Cr2O72
2 : K2Cr2O2
3 : Cr2(SO4)3
4 : K2CrO4
18 : In which compound oxidation state of chloride is +5:
1 : NaCl
2 : NaClO2
3 : HOCl
4 : NaClO3
19 : In reaction 3Fe + 3Cl2 → 2FeCl3:
1 : Fe is reduced
2 : Fe is oxidized
3 : Cl2 is oxidized
4 : none of these
20 : In which of the following changes there is a transfer of five electrons?
1 : MnO4-2 → MnO4-1
2 : MnO4-1 → Mn2+
3 : CrO42- → Cr3+
4 : CrO7.2- → 2Cr+3
21 : In conversion of Br2 to BrO3- the oxidation state of bromine changes from:
1 : 0 to -2
2 : 0 to -3
3 : 2 to 5
4 : 0 to 5
22 : The process during which one metal is deposited on the surface of another metal by using electrical current is called:
1 : Electrolysis
2 : Electroplating
3 : electrolytic refining
4 : Electrolytic purification
23 : The reaction 2K2MnO4 + 2KMnO4 is:
1 : Chlorination of K2MnO4
2 : Neutralization reaction
3 : Oxidation reduction reaction
4 : Neither oxidation nor reduction
24 : In which of the following reaction does hydrogen behave as an oxidizing agent?
1 : H2 + Cl2 → 2 HCl
2 : C2H4 + H2 → C2H6
3 : 2 Na + H2 → 2 NaH
4 : N2 + 3H2 → 2 NH3
25 : Electrolysis is the process in which a chemical reaction takes place at the expense of:
1 : Chemical energy
2 : electrical energy
3 : urease
4 : invertase
26 : Which of the following cannot conduct electricity?
1 : NaCl solid
2 : NaCl fused
3 : NaCl (aq)
4 : Both B and C
27 : How many faradays are required to convert Cu2+ to Cu (s)
1 : 1 faraday
2 : 2 faraday
3 : 3 faraday
4 : 4 faraday
28 : An electric current of 1.00 A was passed through a solution of dilute sulfuric acid for 1.00 min, the quantity of charge passed is?
1 : 1 C
2 : 3600 C
3 : 2 C
4 : 60 C
29 : In standard hydrogen electrode:
1 : 1.0M HCl solution
2 : H2 gas at 1 atm pressure
3 : Platinum electrode
4 : All of the above
30 : Standard Hydrogen Electrode (SHE) is made of:
1 : Ag foil
2 : Au foil
3 : Cu foil
4 : Pt foil
31 : Cell potential of Zn-Cu cell is:
1 : 0.0 V
2 : 0.5 V
3 : 1.0 V
4 : 1.1 V
32 : A cell in which electric current is produced as a result of spontaneous redox reaction is called:
1 : Electrolyte cell
2 : Galvanic cell
3 : Half cell reaction
4 : Dry cell
33 : Study the following facts and indicates which process is feasible? Zn → Zn+2 + 2e- E⁰ = +0.76 V Cu → Cu+2 + 2e- E⁰ = -0.34 V
1 : Cu + Zn+2 → Cu+2 + Zn
2 : Cu+2 + Zn → Cu + Zn+2
3 : Cu+2 + Zn+2 → Cu + Zn
4 : Cu+2 + Zn+2 → Cu + Zn+2
34 : The best oxidizing agent is:
1 : F2
2 : Cl2
3 : Br2
4 : I2
35 : When aluminium electrode is coupled with copper electrode in a galvanic cell:
1 : Reduction takes place at copper electrode
2 : Oxidation takes place at copper electrode
3 : Reduction takes place at aluminum electrode
4 : Both (B) and (C)
36 : The overall positive value for the reaction potential predicts that process is energetically:
1 : Not feasible
2 : Feasible
3 : Impossible
4 : No indication
37 : Value of standard reduction potential for strong reducing agents is:
1 : Large positive value
2 : Zero
3 : Large negative value
4 : any of the above
38 : Biochemical oxygen demand (BOD) is the capacity of organic matter in natural water to consume oxygen within a period of:
1 : Three days
2 : Four days
3 : Five days
4 : Six days
39 : In water the concentration of dissolved O2 should be:
1 : 1-3 ppm
2 : 2-5 ppm
3 : 5-8 ppm
4 : 8-12 ppm
40 : In polluted water the dissolved oxygen may be:
1 : 6-8 ppm
2 : 5-8 ppm
3 : 9-10 ppm
4 : 1-3 ppm
41 : Which of the following is used in Winkler method to determine the amount of dissolved oxygen?
1 : KI
2 : NaCl
3 : organic matter
4 : both (A,B)
42 : According to the activity series, which of the following metals would most readily displace hydrogen gas from dilute acids?
1 : Copper (Cu)
2 : Silver (Ag)
3 : Magnesium (Mg)
4 : Platinum (Pt)
43 : The activity series of metals arranges metals in order of their:
1 : Atomic mass
2 : density
3 : ease of oxidation
4 : ease of reduction
44 : The salt bridge allows transfer of -------- in Zn-Cu voltaic cell.
1 : Zn2+ ions
2 : SO4-2 ions
3 : Both
4 : None of these
45 : In Zn-Cu galvanic cell works ideally after complete discharge, both compartments will have:
1 : CuSO4 solution
2 : ZnSO4 solution
3 : Cu2+ ions
4 : Zn solid
46 : Which of the following half-reaction represents a reduction process?
1 : Zn(s) → Zn2+(aq) + 2e-
2 : Fe2+(aq) → Fe3+(aq) + 2e-
3 : Cu+(aq) → Cu2+(aq) + e-
4 : 2Cu+(aq) + Cu(s)
47 : If salt bridge is not used between two half cells in galvanic cell, then the voltage:
1 : Decrease slowly
2 : Decrease rapidly
3 : Does not change
4 : Drop to zero
48 : In an electrolysis experiment, if a change of 96,500 coulombs is passed through a solution, the amount of substance liberated or deposited at the electrode is directly related to:
1 : Mass number of the ion
2 : one mole of electron being transferred
3 : Avogadro's number of ions being discharged
4 : Standard electrode potential of metal ions
49 : The experimental determination of Avogadro's number through electrolysis typically involves measuring:
1 : The current and voltage applied
2 : The mass of the substance deposited or liberated by a known charge
3 : The conductivity of the electrolytic solution
4 : The temperature changes during electrolysis
50 : The principal of measuring DO by Winkler's method is based on:
1 : Iodimetry
2 : Iodometry
3 : Acid-Base titration
4 : Complexometry
51 : A positive value for the standard electrode potential (E⁰) of a metal ions/metal half-cell (e.g., Cu2+ / Cu) indicates that:
1 : The metal is a strong reducing agent
2 : The metal ion is readily oxidized
3 : The metal ion is readily reduced
4 : The metal will readily displace hydrogen from dilute acids
52 : Which of the following changes would typically lead to an increase in the rate of electrolysis?
1 : decreasing the concentration of the electrolyte
2 : increasing the distance between electrode
3 : decreasing the surface area of the electrode
4 : increasing the current passed through the electrolytic cell
53 : In MgCl2, the oxidation of Cl is:
1 : zero
2 : +2
3 : -2
4 : -1
54 : Oxidation state of Mn in K2MnO4 and MnSO4 is in the order:
1 : +7, +6, +2, +4
2 : +6, +7, +2, +4
3 : +7, +6, +4, +2
4 : +4, +6, +7, +2
55 : In SO4-2 the oxidation number of sulphur is:
1 : -8
2 : +8
3 : -6
4 : +6
56 : Which one pair has the same oxidation state of Fe?
1 : FeSO4 and FeCl3
2 : FeCl2 and FeCl3
3 : FeSO4 and FeCl2
4 : Fe2(SO4)3 and FeSO4
57 : Which one of the following is a redox reaction?
1 : NaCl + AgNO3 → NaNO3 + AgCl
2 : Cl2 + 2e- → 2Cl-
3 : 2Na + Cl2 → 2NaCl
4 : Na+ + le- → Na
58 : In all oxidation reactions, atoms of an element in a chemical species lose electrons and increase their:
1 : oxidation states
2 : reduction
3 : electrode
4 : negative charge
59 : Oxidation state of Cl in NaCl and NaOCl is:
1 : -1, +1
2 : 2, -1
3 : -1, 2
4 : none
60 : Oxidation state of chromium in K2CrO4 is:
1 : 5
2 : 6
3 : 3
4 : 7
61 : The common oxidation state of halogen is?
1 : +1
2 : 0
3 : -1
4 : -2
62 : The oxidation number of chromium in K2Cr2O7 is:
1 : 14
2 : 12
3 : 6
4 : 13
63 : Study the following redox reaction: 10Cl- + 16H+ + 2MnO4- → 5Cl2 + 2Mn+2 + 8H2O
1 : Manganese is oxidized from +7 to +2
2 : Chlorine ions are reduced from -1 to zero
3 : Chlorine is reduced from zero to -1
4 : Manganese is reduced from +7 to +2
64 : In which reaction HYDROGEN behave as oxidizing agent?
1 : H2 + Cl2 → 2HCl
2 : 2Na + H2 → 2NaH
3 : C2H2CHO + H2 → C2H5CH2OH
4 : C2H4 + H2 → C2H6
65 : Oxidation number of sulphur in SO42- is:
1 : +6
2 : +4
3 : -6
4 : +2
66 : During oxidation process, oxidation number of an element:
