Electrochemistry

At 300 K , the molar conductivities of the aqueous solutions of three salts at two different concentrations are given below :


Salt
Concentration (M)
Molar conductivity (S cm2 mol−1)


NaNO3
0.01
111


...

An electrochemical cell is fueled by the combustion of butane at 1 bar and 298 K . Its cell potential is $\frac{\boldsymbol{X}}{F} \times 10^3$ volts, where $F$ is the Faraday constant. The value of $\boldsymbol{X}$ is _____________.
Use: S...

In an electrochemical cell, dichromate ions in aqueous acidic medium are reduced to Cr3+. The current (in amperes) that flows through the cell for 48.25 minutes to produce 1 mole of Cr3+ is ______.Use: 1 Faraday = 96500 C mol−1

An aqueous solution of hydrazine $\left(\mathrm{N}_2 \mathrm{H}_4\right)$ is electrochemically oxidized by $\mathrm{O}_2$, thereby releasing chemical energy in the form of electrical energy. One of the products generated from the electroche...

In a conductometric titration, small volume of titrant of higher concentration is added stepwise to a larger volume of titrate of much lower concentration, and the conductance is measured after each addition.

The limiting ionic conductivit...

Plotting $1 / \Lambda_{\mathrm{m}}$ against $\mathrm{c} \Lambda_{\mathrm{m}}$ for aqueous solutions of a monobasic weak acid $(\mathrm{HX})$ resulted in a straight line with $\mathrm{y}$-axis intercept of $\mathrm{P}$ and slope of $\mathrm{...

Consider the strong electrolytes $Z_{m} X_{n}, U_{m} Y_{p}$ and $V_{m} X_{n}$. Limiting molar conductivity ( $\Lambda^{0}$ ) of $\mathrm{U}_{\mathrm{m}} \mathrm{Y}_{\mathrm{p}}$ and $\mathrm{V}_{\mathrm{m}} \mathrm{X}_{\mathrm{n}}$ are 250 ...

The reduction potential $\left(E^{0}\right.$, in $\left.\mathrm{V}\right)$ of $\mathrm{MnO}_{4}^{-}(\mathrm{aq}) / \mathrm{Mn}(\mathrm{s})$ is __________.

[Given: $E_{\left(\mathrm{MnO}_{4}^{-}(\mathrm{aq}) / \mathrm{MnO}_{2}(\mathrm{~s})\...

At 298 K, the limiting molar conductivity of a weak monobasic acid is 4 \(\times\) 102 S cm2 mol\(-\)1. At 298 K, for an aqueous solution of the acid the degree of dissociation is \(\alpha\) and the molar conductivity is y \(\times\) 102 S ...

At 298 K, the limiting molar conductivity of a weak monobasic acid is 4 \(\times\) 102 S cm2 mol\(-\)1. At 298 K, for an aqueous solution of the acid the degree of dissociation is \(\alpha\) and the molar conductivity is y \(\times\) 102 S ...

Some standard electrode potentials at 298 K are given below :Pb2+ /Pb = \(-\)0.13 VNi2+ /Ni = \(-\) 0.24 VCd2+ /Cd = \(-\) 0.40 VFe2+ /Fe = \(-\) 0.44 VTo a solution containing 0.001 M of X2+ and 0.1 M of Y2+, the metal rods X and Y are in...

Consider a 70% efficient hydrogen-oxygen fuel cell working under standard conditions at 1 bar and 298 K. Its cell reaction is \({H_2}(g) + {1 \over 2}{O_2}(g)\buildrel {} \over \longrightarrow {H_2}O(l)\)The work derived from the cell on t...

Molar conductivity (\(\Lambda\)m) of aqueous solution of sodium stearate, which behaves as a strong electrolyte, is recorded at varying concentrations (C) of sodium stearate. Which one of the following plots provides the correct representa...

Consider an electrochemical cell :
\(A\left( s \right)\left| {{A^{n + }}\left( {aq,2M} \right)} \right|{B^{2n + }}\left( {aq,1M} \right)\left| {B\left( s \right).} \right.\)
The value of \(\Delta {H^ \circ }\) for the cell reaction is twi...

For the electrochemical cell,
\(\left. {Mg\left( s \right)} \right|M{g^{2 + }}\left( {aq,1\,M} \right)\left\| {C{u^{2 + }}} \right.\left( {aq,1M} \right)\left| {Cu\left( s \right)} \right.\)
the standard \(emf\) of the cell is \(2.70\) $$V...

For the following cell,
\(Zn\left( s \right)\left| {ZnS{O_4}\left( {aq} \right)} \right|\left| {CuS{O_4}\left( {aq} \right)} \right|Cu\left( s \right)\)
when the concentration of \(Z{n^{2 + }}\) is \(10\) times the concentration of $$C{u^{2...

The conductance of a \(0.0015\) \(M\) aqueous solution of a weak monobasic acid was determined by using a conductivity cell consisting of platinized \(Pt\) electrodes. The distance between the electrodes is \(120\) \(cm\) with an area of cr...

For the following electrochemical cell at 298 K
Pt(s) | H2 (g, 1 bar) | H+ (aq, 1 M) || M4+ (aq), M2+ (aq) | Pt (s)
Ecell = 0.092 V when \({{\left[ {{M^{2 + }}(aq)} \right]} \over {\left[ {{M^{4 + }}(aq)} \right]}}\) = 10x
Give, $$E_{{M^{4...

The molar conductivity of a solution of a weak acid HX (0.01 M) is 10 times smaller than the molar conductivity of a solution of a weak acid HY (0.10 M). If \(\lambda _{{x^ - }}^0 \approx \lambda _{{y^ - }}^0\) the difference in their pKa v...

All the energy released from the reaction \(X \to Y, \Delta _tG^o\) = -193 kJ mol-1 is used for oxidizing M+ as M+ \(\to\) M3+ + 2e-, Eo = -0.25 V
Under standard conditions, the number of moles of M+ oxidized when one mole of X is convert...

In a galvanic cell, the salt bridge

The standard reduction potential data at 25oC is given below:
Eo (Fe3+ , Fe2+) = +0.77V;
Eo (Fe2+ , Fe) = -0.44V;
Eo (Cu2+ , Cu) = +0.34V;
Eo (Cu+ , Cu) = +0.52V;
Eo [O2(g) + 4H+ + 4e- \(\to\) 2H2O] = +1.23V;
Eo [O2(g) + 2H2O + 4e- $$\...

An aqueous solution of X is added slowly to an aqueous solution of Y as shown in List – I. The variation in
conductivity of these reactions in List – II. Match List – I with List – II and select the correct answer using
the code given below...

The electrochemical cell shown below is a concentration cell. M | M2+ (saturated solution of a sparingly soluble salt, MX2) || M2+ (0.001 mol dm–3) | M The emf of the cell depends on the difference in concentrations of M2+ ions at the two e...

The electrochemical cell shown below is a concentration cell. M | M2+ (saturated solution of a sparingly soluble salt, MX2) || M2+ (0.001 mol dm–3) | M The emf of the cell depends on the difference in concentrations of M2+ ions at the two e...

Consider the following cell reaction:
2Fe(s) + O2(g) + 4H+(aq) \(\to\) 2Fe2+ (aq) + 2H2O (l); Eo = 1.67 V
At [Fe2+] = 10-3 M, P(O2) = 0.1 atm and pH = 3, the cell potential at 25oC is

AgNO3(aq.) was added to an aqueous KCl solution gradually and the conductivity of the solution was measured. The plot of conductance (\(\Lambda\)) versus the volume of AgNO3 is

The concentration of potassium ions inside a biological cell is at least twenty times higher than the outside. The resulting potential difference across the cell is important in several processes such as transmission of
nerve impulses and m...

The concentration of potassium ions inside a biological cell is at least twenty times higher than the outside. The resulting potential difference across the cell is important in several processes such as transmission of
nerve impulses and m...

For the reduction of NO\(_3^ -\) ion in an aqueous solution, E\(^0\) is + 0.96 V. Values of E\(^0\) for some metal ions are given below:
$$\matrix{
{{V^{2 + }}(aq.) + 2{e^ - } \to V} & {{E^0} = - 1.19\,V} \cr
{F{e^{3 + }}(aq.) + 3...

Electrolysis of dilute aqueous NaCl solution was carried out by passing 10 milli ampere current. The time required to liberate 0.01 mol of H\(_2\) gas at the cathode is (1 Faraday = 96500 C mol\(^{-1}\)].

Sodium fusion extract, obtained from aniline, on treatment with iron (II) sulphate and \(\mathrm{H}_{2} \mathrm{SO}_{4}\) in presence of air gives a Prussian blue precipitate. The blue colour is due to the formation of

While \(\mathrm{Fe}^{3+}\) is stable, \(\mathrm{Mn}^{3+}\) is not stable in acid solution because

Among the following, identify the correct statement.

The total charge (coulombs) required for complete electrolysis is:

If the cathode is a Hg electrode, the maximum weight (g) of amalgam formed from this solution is:

The total number of moles of chlorine gas evolved is :

Ammonia is always added in this reaction. Which of the following must be incorrect?

When ammonia is added to the solution, pH is raised to 11 . Which half-cell reaction is affected by pH and by how much?

$$ \begin{array}{r} 2 \mathrm{Ag}^{+}+\mathrm{C}_6 \mathrm{H}_{12} \mathrm{O}_6+\mathrm{H}_2 \mathrm{O} \rightarrow 2 \mathrm{Ag}(\mathrm{~s})+\mathrm{C}_6 \mathrm{H}_{12} \mathrm{O}_7 +2 \mathrm{H}^{+} \end{array} $$
Find $\ln \mathrm{K}$ ...

We have taken a saturated solution of AgBr. Ksp of AgBr is 12 \(\times\) 10-14. If 10-7 mole of AgNO3 are added to 1 litre of this solution find conductivity (specific conductance) of this solution in terms of 10-7 S m-1 units. Given, molar...

(A) Calculate \(\Delta_r G^\circ\) of the following reaction
\(A{g^ + }(aq.) + C{l^ - }(aq.) \to AgCl(s)\)
Given :
\(\mathrm{\Delta_r G^\circ(AgCl)\quad-109~kJ/mole}\)
\(\mathrm{\Delta_r G^\circ(Cl^-)\quad-129~kJ/mole}\)
$$\mathrm{\Delta_r ...

(a). For the reaction
Ag+ (aq) + Cl- (aq) \(\leftrightharpoons\) AgCl (s)
Given:

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Find the equilibrium constant for the reaction,
In2+ + Cu2+ \(\to\) In3+ + Cu+ at 298 K given
\(E_{C{u^{2 + }}/C{u^ + }}^o\) = 0.15 V; \(E_{l{n^{2 + }}/l{n^ + }}^o\) = -0.40 V; \(E_{l{n^{3 + }}/l{n^ + }}^o\) = -0.42 V;

Two students use the same stock solution of ZnSO4 and solution of CuSO4. The emf of one cell is 0.03 V higher than other. The conc. of CuSO4 in the cell with higher emf value is 0.5 M. Find out the conc. of CuSO4 in the other cell (2.203 RT...

The standard potential of the following cell is 0.23V at 15oC and 0.21 V at 35oC.
Pt | H2 (g) | HCl (aq) | AgCl (s) | Ag (s)
(i) Write the cell reaction.
(ii) Calculate \(\Delta H^o\) and \(\Delta S^o\)m for the cell reaction by assuming th...

The following electrochemical cell has been set up.
Pt(1) | Fe3+, Fe2+ (a = 1) | Ce4+, Ce3+ (a=1) | Pt(2)
Eo (Fe3+, Fe2+) = 0.77 V; Eo (Ce4+, Ce3+) = 1.61 V
If an ammeter is connected between the two platinum electrodes, predict the directi...

Copper sulphate solution (250 mL) was electrolysed using platinum anode and a copper cathode. A constant current of 2mA was passed for 16 minutes. It was found that after electrolysis the absorbance of the solution was reduced to 50% of its...

A cell, Ag | Ag+ || Cu2+ | Cu, initially contains 1 M Ag+ and 1 M Cu2+ ions. Calculate the change in the cell potential after the passage of 9.65 A current for 1 h.

Find the solubility product of a saturated solution of Ag2CrO4 in water at 298 K if the emf of the cell Ag|Ag+ (satd. Ag2CrO4 soln.) || Ag+ (0.1 M) | Ag is 0.164 V at 298 K.