On the basis of the following data, explain why Co(III) is not stable in aqueous solution ?
\({ Co }^{ 3+ }+{ e }^{ - }\longrightarrow { Co }^{ 2+ },{ E }^{ 0 }=+1.82V\)
\(2{ H }_{ 2 }O\longrightarrow { O }_{ 2 }+4{ H }^{ + }+{ 4e }^{ - },{ E }^{ 0 }=1.23V\)

A voltaic cell is set up at \(25°\)C with the half cells Ag⁺(0.001 M)Ag and Cu²⁺(0.10M)Cu. What should be its cell potential?

India is a very big country and is in a phase of modernisation. There is an enormous shortage of electricity and as a result, our industrial growth is hampered. There are major cuts both at household and domestic levels. These days, there is a major emphasis on the use of solar energy.
(i) How is the solar power used in a country like India?
(ii) As a student, how will you promote the use of solar power?

Calculate the \(\triangle G^{ 0 }\)   and emf (E) that can be obtained from the following cell under the standard conditions at 25°C. Zn(s) IZn²⁺(aq) IISn²⁺(aq) I Sn(s) [Given \(E^{ 0 }_{ Zn2+/Zn }=-0.76V;\) \(E^{ 0 }_{ sin2+/sn }=-0.14V\) ] and F = 96500 C mol^-1

(i) The conductivity of 0.001 mol L^-1 solution of CH₃COOH is 3.905 x 10^-5 S cm^-1. Calculate its molar conductivity and degree of dissociation. Given \(\lambda ^{ 0 }\left( H^{ + } \right) =349.6 \ Scm^{ 2 } \ mol^{ -1 }\) and \(\lambda ^{ 0 }\left( CH_{ 3 }COO^{ - } \right) =40.9 \ scm^{ 2 }mol^{ -1 }\)
(ii) Define electrochemical cell. What happens if external potential applied becomes greater than E⁰_cell of electrochemical cell?

Observe the diagram carefully and answer the questions below:
An external opposite potential is applied such that it exceeds the cell potential.
a. Is this an electrochemical cell or electrolytic cell?
b. Which substance gets dissolved?
c. Which substance gets deposited and where?
d. Write half cell reactions.
e. Is the needle in the voltmeter correctly marked?

2 beakers A and B contain 1 M ZnSO₄ solution. To A , Strip of Mg is dipped, while in B, A zinc rod is put. If both are connected to a standard hydrogen electrode, which cell would show a deflection? Explain with suitable reason.

The standard electrode potentials of different electrodes are given as
E⁰ Co³⁺ /Co 2+ = 1.81 V, E⁰ Al 3+ /Al = -1.66 V, E⁰ Fe ²⁺ /Fe = -0.44 V, E⁰ _Br2/Br- = 1.01 V
a. Identify all the possible combination for construction of a feasible electrochemical cell?
b. Write their electrochemical cell representation.
c. Calculate the emf in each case.

a. During electrolysis of NaOH, Cl₂ and H₂ while for molten NaCl only Na metal and Cl₂ gas are obtained. Explain these observations with suitable eqn.
b. Electrolysis of conc. and dil. sulphuric acid are different. Explain with eqn.

An Aq. solution of AuCl₃ was electrolysed with a current of 0.5A until 1.20g of Au had been deposited on the cathode. At another electrode in series with this, the only reaction was evolution of O₂. Find—
1. The no. of moles
2. The volume at NTP
3. The mass of O₂ liberated
4. the no. of coulombs passed through the solution and
5. the duration of electrolysis