Assignment – 1
Electrochemistry
Q 1. How much electricity in terms of Faraday
is required to produce 100g of Ca from molten CaCl2?
Q 2. Name the solid substance produced, during
the discharge of lead- storage battery.
Q 3. If 0.5 ampere current flows through a wire
for 2 hours. Calculate the number of electrons through the wire.
Q 4. Write importance of salt bridge in a
Galvanic cell?
Q 5. What is fuel cell? Write two chemicals which can be used as
fuel.
Q 6. How many moles of mercury will be produced
by electrolysing 1.0 M Hg (NO3)2 solution with a current
of 2.00 A for three hours? Molar mass of Hg(NO3)2 = 200.6
g/mol
Q 7. Represent the galvanic cell in which the
following reactions take place
Zn(s) + 2 Ag+(aq) → Zn2+(aq)
+ 2 Ag(s)
ü Which
one of the electrodes is negatively charged?
ü Write
the reaction taking place at each of the electrodes.
ü Name
the carrier of current within the cell.
Q 8. State Faraday's laws. How much charge is
required for the reduction of 1 mole of Cu2+ to Cu?
Q 9. What is the role of ZnCl2 in a
dry cell?
Q 10. Write two advantages of H2-O2
fuel cell.
Q 11. Determine the value of equilibrium constant
and ΔG0 for the following reaction:
Ni(s) + 2 Ag+(aq) → Ni2+
(aq) + 2 Ag(s) (E0 = 1.05V)
Q 12. Calculate the standard electrode potential of
Ni2+// Ni electrode if emf of the Ni2+/Ni(0.01) // Cu2+(0.1)
/ Cu (s) electrochemical cell is 0.059V.
Given E0 = 0.34V.
Q 13. Why does a Galvanic cell become dead after
some time?
Q 14. The
following is a plot of molar conductivity of electrolytes A and B against
square root of concentration
ü Write
the mathematical relationship between ƛm and C for strong electrolytes (A)
ü Identify
the curves represented by strong electrolyte (A) and weak electrolyte (B)
ü What
does m represent? Give one method for determining ƛm of the electrolyte (B)
Q 15. The conductivity of 0.20 m solution of KCl at
298 K is 0.02485 cm-1. Calculate its molar conductivity.
Q 16. The resistance of conductivity cell filled
with 0.1 M KCl solution is 100 Ohm. If the resistance of the same cell when
filled with 0.02 M KCl solution is 520 ohm. Calculate the conductivity and
molar conductivity of 0.02 M KCl solution. Conductivity of 0.1 M KCl solution
is 1.29 m–1.
Q 17. λm for
NaCl, HCl & NaAc are 126.4, 425.9 & 91.05 cm2 mol-1
respectively. Calculate λom for HAc. (Ac stands for acetate)
Q 18. The Eo cell for Daniel cell is 1.1
V. Calculate the standard Gibbs energy for the reaction:
Zn (s) + Cu2+ (aq) → Zn2+ (aq)
+ Cu (s)
Q 19. Account for the following:-
ü Alkaline
medium inhibits the rusting.
ü Iron
does not rusted even if zinc coating is broken down at any point in a
galvanized pipe.
Q 20. I) Define the molar conductivity of a solution
and explain how molar conductivity changes with change in concentration of solution for a weak and strong electrolyte.
ii). The resistance of a
conductivity cell containing 0.001M KCl solution at 298K is 1500Ω. What is the cell constant, if
the conductivity of 0.01M KCl solution at 298 K is 0.146 X (10–3) S cm–1?
0 Comments