Previous Year Papers

Download Solved Question Papers Free for Offline Practice and view Solutions Online.

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.

291. Determine the equilibrium constant of the reaction at 298 K.
$2 {Fe}^{3 +} + {Sn}^{2 +} ⇋ 2 {Fe}^{2 +} + {Sn}^{4 +}$
From the obtained value of the equilibrium constant, predict whether Sn²⁺ ions can reduce Fe³⁺to Fe²⁺ quantitatively or not.
$E °_{{Sn}^{4 +} / {Sn}^{2 +}} = 0.15 V and E °_{{Fe}^{3 +} / {Fe}^{2 +}} = + 0.77 V$

The cell is
$Pt (s) | {Sn}^{2 +} (aq) | {Sn}^{4 +} | (aq) | | {Fe}^{3 +} (aq) | {Fe}^{2 +} (aq) | Pt (s)$
and $E °_{cell} = E °_{{Fe}^{3 +} / Fe} - E °_{{Sn}^{4 +} / {Sn}^{2 +}} = + 0.77 - (+ 0.15) = + 0.62 V$
and n = 2
∴ $K = antilog (\frac{nE °}{0.059}) = antilog (\frac{2 \times 0.62}{0.059}) = antilog (21.0169)$
$K = 1.039 \times 10^{21}$
As K is very high, the reaction is favoured in the forward direction, so, Sn²⁺ can easily reduce Fe³⁺ion to Fe²⁺ ion.

145 Views

292. Calculate the equilibrium constant for the reaction at 298 K

Cu (s) + {Cl}_{2} (g) ⇌ {CuCl}_{2} (aq)

Given:

E °_{{Cu}^{2 +} / Cu} = 0.34 V; E °_{{Cl}^{2 +} / {Cl}^{-}} = 1.36 V, R = 8.314 J K^{- 1} {mol}^{- 1}

784 Views

293. Calculate the equilibrium constant K_c for the reaction at 298 K.

3 {Sn}^{4 +} + 2 Cr ⇋ 3 {Sn}^{2 +} + 2 {Cr}^{3 +}

(Given E °_{{Sn}^{4 +} / {Sn}^{2 +}} = 0.15 V; E °_{{Cr}^{3 +} / Cr} = - 074 V) . = 0.34 V;

155 Views

294. Calculate the equilibrium constant for the cell reaction:

4 {Br}^{-} + O_{2} + 4 H^{+} \to 2 {Br}_{2} + 2 H_{2} O

(Given

E °_{cell} = 0.16

)

181 Views

Long Answer Type

295. Calculate the potential (emf.) of the cell
Cd | Cd²⁺ (0.10 M) || H⁺(0.20 M) | Pt, H₂ (0.5 atm)
(Given : E° _{Cd2+ / Cd} = – 0.403 V, R = 8.314 K^–1 K^–1 mol^–1, F = 96500 C mol^–1)

595 Views

Short Answer Type

296. Calculate ΔG° for the reaction

{Cu}^{2 +} (aq) + Fe (s) \to {Fe}^{2 +} (aq) + Cu (s) (Given E °_{{Cu}^{2 +} / Cu} = 0.34 V, E °_{{Fe}^{3 +} / Fe} = - 0.44 V, F = 96500 e {mol}^{- 1})

128 Views

297. The standard electrode potential for Daniell cell is 1.1 V. Calculate the standard Gibbs energy for the reaction:

Zn (s) + {Cu}^{2 +} (aq) \to {Zn}^{2 +} (aq) + Cu (s)

1162 Views

298.

Calculate the Δ_r G° and the equilibrium constant for the reaction
2Cr(s) + 3Cd²⁺ (aq) 2Cr³⁺ (aq) + 3Cd(s)
(Given E°_Cr3+_/Cr = 0.74 V, E°_{Cd2+/ Cd} = – 0.40 V)

154 Views

299.

Calculate the cell e.m.f. and ΔG for the cell reaction at 298 K for the cell
Zn(s) | Zn²⁺ (0.0004 M) || Cd²⁺(0.2 M) | Cd(s)
(Given E°_Zn²⁺/Zn = 0.763 V, E°_{cd 2+ / cd} = 0.403 Vat 298 K, F = 96500 C mol^–1)

333 Views

300. Calculate the cell emf and AG for the cell rection at 25°C for the cell
Zn(s) | Zn²⁺ (0.0004 M) || Cd²⁺ (0.2 M) | Cd(s) E° values at 25°C, Zn²⁺/Zn = – 0.763 V, Cd²⁺/ Cd = – 0.403 V F = 96500 C mol^–1, R = 8.314 J K^–1 mol^–1

107 Views

Previous Year Papers

Test Series

Test Yourself

Short Answer Type

291. Determine the equilibrium constant of the reaction at 298 K.2Fe3++Sn2+ ⇋ 2Fe2++Sn4+From the obtained value of the equilibrium constant, predict whether Sn2+ ions can reduce Fe3+ to Fe2+ quantitatively or not.E°Sn4+/Sn2+ = 0.15 V and E°Fe3+/Fe2+ = +0.77 V

Long Answer Type

Short Answer Type