Electrochemistry is a branch of chemistry that deals with the quantitative study of the inter-relationships between chemical energy and electrical energy, as well as the inter-conversion of one form into another relationships between electrical energy in redox reactions.
Download Class 12 Chemistry Worksheet on Chapter 3 Electrochemistry Set 2 PDF.
CBSE Class 12 Chemistry Chapter 3 Electrochemistry Worksheet – Set 2
Q-1: The molar conductivity of a 0.01 M weak acid (HX) at 298 is 64.4 Scm2mol-1 when measured in a conductivity cell with a cell constant of 0.4 cm-1. At 298 K, the limiting molar conductivities of H+ and X– at infinite dilution are 350 and 410 Scm2mol-1, respectively. Without taking into account activity coefficients, the pKa of HX at 298 K is_____________ . (upto two decimal places)
Q-2: The Latimer diagram of oxygen is given below. The value of x is _______V(Up to two decimal places)
Q-3: A platinum electrode is immersed in a solution containing 0.1 M Fe2+ and 0.1 M Fe3+. Its potential is found to be 0.77 V against SHE. Under standard conditions and considering activity coefficients to be equal to unity, the potential of electrode when the concentration of Fe3+ is increased to 1 M is_________
Q-4: Depict the galvanic cell in which the reaction Mg (s) + 2Ag+ → Mg2+ + 2Ag (s) takes place.
Additionally, demonstrate:
(a) Which of the electrodes is negatively charged ?
(b) The carriers of the current in the cell.
(c) Individual reaction at each electrode
Q-5: Why is alternating current used to measure electrolytic solution resistance?
Q-6: Given the standard potential for the following half cell reaction at 298 K,
Cu+(aq) + e– → Cu(s) EO= 0.52 V
Cu2+(aq) + e– → Cu+(aq) EO= 0.16 V
Calculate the ΔGo(kJ) for the reaction, [ 2Cu+(aq) → Cu(s) + Cu2+]
Q-7: Eo (Cu2+/Cu) is + 0.337 V, while Eo (Ag+/Ag) is + 0.799 V. Create a cell with a positive EMF. Calculate the concentration of Ag+ if the concentration of Cu2+ is 0.01M and Ecell at 25oC is zero.
Q-8: The standard reduction potential values for MnO4–, Ce4+ and Cl2 are 1.507,1.61 and 1.358 V respectively. Arrange these in order of increasing strength as oxidising agents.
Q-9: Electrochemical equivalent of an element is
- Atomic weight × Valency/ 96500
- Atomic weight × 96500/ Valency
- Atomic weight / (Valency × 96500)
- (Valency × 96500)/Atomic weight
Q-10: An electric current of 0.965 amps is passed through a solution containing [Cu(CH3CN)4]+ for 2000 seconds, and metallic copper is deposited at the cathode. The amount of Cu that has been deposited in moles is
- 0.005 mol
- 0.01 mol
- 0.02 mol
- 0.04 mol
Q-11: A 19th century iron bridge is protected from corrosion by connecting it to a metal block (sacrificial mode) that is replaced annually. Iron corrosion, as represented by equation
2Fe(s) + 2H2O(l) + O2(g) → 2Fe(OH)2
EO: Fe2+ + 2e– → Fe(s) -0.44 V
2H2O + O2 +4e– → 4OH– +0.40V
Which of the following metals is best suited as sacrificial anode?(Reduction potential value are given)
- Ag: +0.80 V
- Cu: 0.34 V
- Cd: -0.40 V
- Mg: -2.36 V
Q-12: The reduction potentials of metals A and B are -0.76 V and + 0.34 V, respectively. Which of these will release H2 from diluted H2SO4?
Q-13: Which one of the following statements is true? With dilution, the equivalent conductance of
- Both strong and weak electrolyte decrease
- Strong electrolyte increases while that of weak electrolyte decreases
- Strong electrolyte decreases while that of weak electrolyte increases
- Both strong and weak electrolyte increases
Q-14: Which of the following curve represents the variation of á´§m with c1/2 for AgNO3?
Q-15: Which of the following statements is/are correct about a standard hydrogen electrode?
a) The temperature is kept at 25 degrees Celsius.
b) The concentration of hydrogen ions is 1M.
c) The pressure of hydrogen gas is kept constant at 1 atm.
d) It has platinum metal in it, which is used to adsorb hydrogen gas.
Q-16: Why is fluorine gas the most powerful oxidising agent and fluoride ion the weakest reducing agent?
Q-17: At 315 K, the conductivity of a saturated solution of BaSO4 is 3.648×10-6 ohm-1cm-1, while that of water is 1.25×10-6 ohm-1cm-1. Ba2+ and SO4 2- have ionic conductances of 110 and 136.6 ohm-1cm2 mol-1, respectively. Determine the solubility of BaSO4 in g/l.
Q-18: Write the electrode reactions for anode and cathode in a mercury cell.
Q-19: Define conductivity and molar conductivity for a solution of an electrolyte.
Q-20: People are advised to limit their use of fossil fuels, which causes the GreenHouse Effect and a global rise in earth’s temperature. In fuel cells, hydrogen is an excellent alternative.
(a) Create electrode reactions for H2 -O2 fuel cells.
(b) Can we substitute CH4 for H2? If so, record the electrode reaction at the anode.
(c) How does the use of fuel cells reduce the greenhouse effect?
(d) Record the values associated with fuel cell preference.
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