This set of Physical Chemistry Multiple Choice Questions & Answers (MCQs) focuses on “Electrochemical Potential and Electrochemical Cells”.
1. Electrochemical series is the list of elements based on hydrogen scale.
a) False
b) True
View Answer
Explanation: It is built by arranging various redox equilibria in order of their standard electrode potential each Eo value shows the position of equilibrium.
2. What is electrode potential of Zn?
a) Depends on the nature of coupled electrode
b) Oxidation-reduction
c) Oxidation
d) Reduction
View Answer
Explanation: Potential difference developed between the metal and the solution, is called electrode potential. The electrode potential of Zn depends on the nature of coupled electrode.
3. What is the name of the chemical used in salt-bridge?
a) KBr
b) KOH
c) KCI
d) KNO3
View Answer
Explanation: KCl is used in the salt bridge because it is very soluble and it provides K+ ions and negative Cl– to the salt bridge.
4. What is the pressure of the H2 gas in SHE?
a) 800mm of Hg
b) 760mm of Hg
c) 780mm of Hg
d) 820mm of Hg
View Answer
Explanation: The Standard Hydrogen Electrode (SHE) is officially the 0.0V thermodynamic reference point for all potential measurements at all temperatures. The pressure of the H2 gas is 760mm of Hg.
5. What is the temperature for the measurement of standard electrode potential?
a) 300 K
b) 298 K
c) 310 K
d) 450 K
View Answer
Explanation: Standard electrode potential is the measure of individual potential of a reversible electrode. The temperature for the measurement is 298 K and pressure is 1 atm.
6. E0red of an element can be calculated by comparing it with?
a) SHE
b) 2 M solution of HCI
c) New electrode of the same element
d) 1 M solution of ions of respective elements
View Answer
Explanation: It is a measure of the tendency to acquire electrons and thereby be reduced. It is measured in V. It can be calculated by comparing with SHE.
7. How can a voltaic cell be recharged?
a) By heating it
b) By removal of solution
c) By adding fresh solution
d) by replacing external circuit with an external source of electricity
View Answer
Explanation: A Voltaic cell can be recharged by replacing external circuit with an external source. During the recharge of the cell, EMF increases because the reactants disappear. Ions move oppositely during charging.
8. What is the potential of SHE?
a) Unity
b) Constant
c) Multiple of 1
d) Zero
View Answer
Explanation: It is a redox electrode. Its absolute electrode potential is estimated to 4.44 ± 0.02 V at 25℃. The potential of SHE is considered as zero.
9. Half cells are connected through salt bridge.
a) False
b) True
View Answer
Explanation: The Salt bridge is a device which is used to connect oxidation and reduction half-cells of a voltaic or galvanic cell.
10. What is the reduction potential of Zn?
a) 0.55
b) -0.55
c) -0.76
d) 0.76
View Answer
Explanation: It is a measure of the tendency of a chemical species to acquire electrons and thereby be reduced. It is measured in V. The reduction potential of Zn is -0.76.
Sanfoundry Global Education & Learning Series – Physical Chemistry.
To practice all areas of Physical Chemistry, here is complete set of Multiple Choice Questions and Answers.
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