Advertisements
Advertisements
Question
Calculate the standard emf of the cell: \[\ce{Cd|Cd^{2+}||Cu^{2+}|Cu}\] and determine the cell reaction. The standard reduction potentials of Cu2+|Cu and Cd2+|Cd are 0.34 V and −0.40 volts respectively. Predict the feasibility of the cell reaction.
Solution
Cell reactions:
Oxidation at anode:
\[\ce{Cd_{(s)} -> Cd^{2+}_{( aq)} + 2e^-}\] \[\ce{(E^0_{ox})_{{Cd|Cd^{2+}}}}\] = 0.4 V
Reduction at cathode:
\[\ce{Cu^{2+}_{( aq)} + 2e^- -> Cu_{(s)}}\] \[\ce{(E^0_{red})_{{Cu^{2+}|Cu}}}\] = 0.34 V
\[\ce{Cd_{(s)} + 2e^- -> Cd^{2+}_{( aq)} + Cu_{(s)}}\]
`"E"_"cell"^0 = ("E"_"ox"^0)_"anode" + ("E"_"red"^0)_"cathode"`
= 0.4 + 0.34
= 0.74 V
emf is +ve, so ΔG is (−)ve, the reaction is feasible.
APPEARS IN
RELATED QUESTIONS
Consider the following half cell reactions:
\[\ce{Mn^{2+} + 2e^- -> Mn}\] E0 = –1.18 V
\[\ce{Mn^{2+} -> Mn^{2+} + e^-}\] E0 = –1.51 V
The E0 for the reaction \[\ce{3Mn^{2+} -> Mn + 2Mn^{3+}}\], and the possibility of the forward reaction are respectively.
The button cell used in watches functions as follows.
\[\ce{Zn_{(s)} + Ag2O_{(s)} + H2O_{(l)} ⇌ 2Ag_{(s)} + Zn^{2+}_{( aq)} + 2OH^-_{( aq)}}\] the half cell potentials are \[\ce{Ag2O_{(s)} + H2O_{(l)} + 2e^- -> 2Ag_{(s)} + 2OH^-_{( aq)}}\] E0 = 0.34 V The cell potential will be
During electrolysis of molten sodium chloride, the time required to produce 0.1 mole of chlorine gas using a current of 3A is ___________.
While charging lead storage battery
Among the following cells
I) Leclanche cell
II) Nickel – Cadmium cell
III) Lead storage battery
IV) Mercury cell
Primary cells are:
In \[\ce{H2 - O2}\] fuel cell the reaction occurs at cathode is:
For the cell reaction
\[\ce{2Fe^{3+}_{( aq)} + 2l^-_{( aq)} -> 2Fe^{2+}_{( aq)} + l2_{( aq)}}\]
\[\ce{E^0_{cell}}\] = at 298 K. The standard Gibbs energy (∆G°) of the cell reactions is:
State Faraday’s Laws of electrolysis.
In fuel cell H2 and O2 react to produce electricity. In the process, H2 gas is oxidised at the anode and O2 at cathode. If 44.8 litre of H2 at 25°C and 1 atm pressure reacts in 10 minutes, what is average current produced? If the entire current is used for electro deposition of Cu from Cu2+, how many grams of deposited?
Derive an expression for the Nernst equation.
