Chemistry Chapter 9 Entry Test MCQs
101. The reaction which takes place at anode during electrolysis of sulphuric acid
a. SO4 −2 → S2O3 2 − + O2 + 4e–
b. 4 OH– → 2H2O + O2 + 4e–
c. 2H+ + 2e- → H2
d. SO4 −2 → SO2 + O2 + 4e–
102. The correct order of chemical reactivity with water according to electrochemical series:
a. K > Zn > Mg > Cu
b. K > Mg > Zn > Cu
c. Cu > Zn > Mg > K
d. Mg > Zn > Cu > K
103. Reduction potential of four elements P, Q, R, S is -2.90, +0.34, +1.20 and –0.76. Reactivity decreases in the order:
a. R > Q > S > P
b. P > Q > R > S
c. P > S > Q > R
d. Q > P > R > S
104. In which one of the following reactions does hydrogen behave as an oxidizing agent?
a. 2𝐻4+𝐻2⟶𝐶2𝐻6
b. 𝐻2+𝐶𝑙2⟶2𝐻𝐶𝑙
c. 𝑁2+3𝐻2⟶2𝑁𝐻3
d. 2Na + 𝐻2⟶2𝑁𝑎𝐻
105. In hydrogen-oxygen fuel cell, the two electrodes are hollow tube made of porous compressed carbon impregnated with platinum which act as?
a. Catalyst
b. Inhibitor
c. Oxidizing agent
d. Reducing agent
106. The trend of strength as oxidizing agent down the electrochemical series is:
a. Variable
b. Increasing
c. Same
d. Decreasing
107. Which statement is correct about electrochemical series?
a. Every top metal can displace lower one while lower non-metal can displace higher one
b. Greater is the standard reduction potential, stronger is the reducing agent.
c. Upper metal act as cathode and lower as anode
d. Smaller is the standard reduction potential, greater is oxidation power.
108. Which is best reducing agent regarding in electrochemical series?
a. Na
b. Li
c. Ca
d. K
109. Which reaction is not feasible?
a. 2KBr +Cl2 →2KCl + Br2
b. 2KI + Br2 → 2KBr + I2
c. 2H2O + 2F2 → 4HF + O2
d. 2KBr + I2 → 2KI + Br2
110. A solution containing one mole per litre of each Cu(NO3)2; AgNO3; Hg2(NO3)2; is being electrolyzed by using inert electrodes. The values of standard electrode potentials in volts (reduction potentials) are
Ag / Ag+ = +0.80, Au / Au+3 = +1.50
Cu / Cu++ = +0.34, Mg / Mg++ = – 2.37
The decreasing sequence of deposition of metals on the cathode will be
a. Cu, Au, Ag
b. Ag, Au, Cu, Mg
c. Mg, Cu, Au, Ag
d. Au, Ag, Cu
111. Group 1 metals are reactive than group 2 metals.
a. Equal
b. More
c. No relation
d. Less
112. Potential of SHE is considered as
a. Constant
b. Zero
c. Multiple of 1
d. Unity
113. Consider the standard reduction potential of the followings, Best oxidizing agent is
Mg+2 + 2e- → Mg Eo = – 2.37 V
Fe+3 + 3e- → Fe Eo = – 0.04 V
a. Fe+3
b. Mg+2
c. Fe
d. Mg
114. That reaction is feasible which has the net cell voltage
a. Zero
b. Positive
c. Negative
d. Any of these
115. The standard electrode potential is measured by
a. Galvanometer
b. Electrometer
c. Polarimeter
d. Voltmeter
116. If reduction potentials of different metals are
a. = – 1.50V
b. = – 0.25V
c. =- 1.27V
d. = – 1.0V
117. The standard reduction potential of two electrodes are given as
A = + 1.36 V B =- 0.44 V the emf of the cell is
a. – 1.36V
b. + 1.36V
c. + 1.80V
d. + 0.92V
118. Li+ has a smaller ionic mobility than K+ because of the:
a. Greater degree of hydration of Li+
b. Larger size of Li+
c. Smaller nuclear charge of Li+
d. Larger radius to charge ratio of Li+
119. When a lead storage battery is discharged
a. SO2 is evolved
b. lead is formed
c. sulphuric acid is consumed
d. lead sulphate is consumed