Chemistry Chapter 9 Entry Test MCQs
76. When a copper wire is placed in a solution of AgNO3, the solution acquires blue colour. This is due to the formation of
a. Cu2+ ions
b. Cu+ ions
c. Cu– ion by the reduction of Cu.
d. soluble complex of copper with AgNO3
77. Of the following metals that cannot be obtained by the electrolysis of the aqueous solution of their salts are
a. Ag and Al
b. Ag and Mg
c. Cu and Cr
d. Mg and Al
78. A dilute aqueous solution of CaCO3 is electrolyzed using platinum electrodes. The product at the anode and cathode are
a. O2, Na
b. O2, H2
c. S2O82-, H2
d. S2O82-, Na
79. The products formed when an aqueous solution of NaBr is electrolyzed in a cell having inert electrodes are
a. H2, Br2, and NaOH
b. Na and Br2
c. H2 and O2
d. Na and O2
80. The electrolysis of one of the following produce different products in molten and aquous state:
a. PbSO4
b. CaSO4
c. MgSO4
d. CuSO4
81. Which is a secondary cell or battery
a. NICAD
b. Lead accumulator
c. Fuel cell
d. All of the above
82. Electrical energy is produced by a simple cell as result of
a. The positive and negative ions combining together
b. The formation of covalent bonds between atoms
c. The transfer of electrons from a more reactive to a less reactive element
d. The formation of negative ions from atoms
83. Which will be released at anode during electrolysis of very dilute solution of common salt:
a. Cl2
b. H2
c. H2 and O2
d. O2
84. In the electrolysis of dil. H2SO4 using platinum electrode, what is true
a. Oxygen is evolved at anode
b. OH– is discharged at the cathode
c. SO2 is evolved at anode
d. H2 is evolved at anode
Electrode potential + SHE + ECS (electrochemical series)
85. The cell reaction of the galvanic cell is Cu | Cu2+ || Hg2+ | Hg
a. Hg + Cu2+ → Hg2+ + Cu+
b. Hg + Cu2+ → Hg2+ + Cu
c. Hg+2 + Cu → Hg + Cu+2
d. Hg + Cu → CuHg
86. Consider the following four electrodes:
a. = Cu2+ (0.01 M) Cu (s)
b. = Cu2+ (0.0001 M) Cu (s)
c. = Cu2+ (0.001 M) Cu (s)
d. = Cu2+ (0.1 M) Cu (s)
87. The standard electrode potential for the reaction Zn + Cu2+ ↔ Cu + Zn2+ is 1.1 V. The electrode potential for the reaction, when 0.1 M Cu2+ and 0.1 M Zn2+ solution is used, will be
a. 11.0 V
b. 1.1 V
c. + 0.011 V
d. -0.11 V
88. Two electrochemical cell are connected in series. What will be the net e.m.f. of the cell at 25oC? Zn | Zn2+ || Cu2+ | Cu and Fe | Fe2+ || Cu2+ |Cu
Given: Zn2+ | Zn = – 0.76 V, Cu2+ | Cu = +0.34 V Fe2+ | Fe = – 0.41 V
a. + 0.83 V
b. + 1.85
c. -0.83 V
d. – 1.85 V
89. The reduction potential values of M, N and O are +2.46, – 1.13 and -3.13 V respectively. Which of the following order is correct regarding their reducing agent?
a. O > M > N
b. O > N > M
c. M > O > N
d. M > N > O
90. The standard oxidation potential E? for the half reactions are as
Zn → Zn2+ + 2e- Eo = + 0.76 V Fe → Fe2+ + 2e- Eo = + 0.41 V The EMF for the cell reaction Fe2+ + Zn → Zn2+ + Fe is
a. -0.35 V
b. + 1.17 V
c. 0.117 V
d. + 0.35 V
91. The standard reduction potential for Fe2+ / Fe and Sn2+ / Sn electrodes are -0.44 and -0.14 volt respectively. For the cell reaction:
Fe2+ + Sn → Fe + Sn2+
The standard emf is
a. – 58 V
b. Z+0.30 V
c. – 0.300 V
d. + 0.58 V
92. Eo cell For a cell given below
Ag | Ag+ || Cu2+ / Cu Eo cell is: +
Ag+ + e– → Ag Eo = x
Cu2+ + 2e– → Cu, Eo = y
a. y – x
b. x + 2y
c. y – 2x
d. 2x + y
93. Stronger the oxidizing agent, higher is:
a. Standard reduction potential
b. Redox potential
c. Oxidation potential
d. Reducing agents
94. Which is the correct trend of oxidizing power in halogen on moving down the group?
a. Cℓ2 > Br2 > F2 > I2
b. F2 > Cℓ2 > Br2 > I2
c. F2 < Cℓ2 < Br2 < I2
d. F2 < Br2 < I2 < Cℓ2
95. What reaction takes place at SHE when Zn half-cell is attached to SHE:
a. Zn + OH- → Zn(OH)2
b. 2H+ + 2e-→ H2
c. Zn++ + 2 e– → Zn
d. H2 → 2H+ + 2e–
96. Which will act as cathode when attached to SHE:
a. Magnesium
b. Copper
c. Lead
d. Nickel
97. Electrochemical series gives idea about reactivity of metals. Metal with lesser value of reduction potential is reactive and displaces the metal with higher value of reduction potential. Among the following, which reaction is NOT feasible?
a. Fe + PbSO4 → FeSO4 + Pb
b. Mg + CuSO4 → MgSO4 + Cu
c. Zn + CuSO4 → ZnSO4 + Cu
d. Cu + FeSO4 → CuSO4 + F
98. Metal that is not deposited at cathode when its aqueous solution is electrolysed
a. Cu2+
b. Au3+
c. Ag+
d. Sn2+
99. Given the two following half reactions,
Ni2+(aq) + 2e- → Ni(s) Eo = -0.25
Hg2+(aq) + 2e- → Hg(l) Eo = +0.86 V
Calculate Eo for the following reaction: Hg2+(aq) + Ni(s) → Ni2+(aq) + Hg(l)
a. + 1.11 V
b. -1.11 V
c. – 0.61 V
d. + 0.61 V
100. The standard oxidation potentials of Zn, Cu, Ag and Ni electrodes are +0.76, – 0.34, – 0.80 and +0.25 V respectively. Which of the following reaction will provide maximum voltage?
a. Cu + 2Ag+ (aq) → Cu2+ (aq) + 2Ag
b. Zn + 2Ag+ (aq) → Zn2+ (aq) + 2Ag
c. Zn + Cu2+ (aq) → Zn2+ (aq) + Cu
d. Zn + 2H+ (aq) → Zn2+ (aq) + H2