Electrochemistry · Chemistry · KCET

How many coulombs are required to oxidise 0.1 mole of $\mathrm{H}_2 \mathrm{O}$ to oxygen?

A current of 3 A is passed through a molten calcium salt for 1 hr 47 min 13 s . The mass of calcium deposited is (Molar mass of $\mathrm{Ca}=40 \mathrm{~g} \mathrm{~mol}^{-1}$ )

The value of ' $A$ ' in the equation $\lambda_{\mathrm{m}}=\lambda_{\mathrm{m}}^{\circ}-A \sqrt{C}$ is same for the pair

The resistance of $$0.1 \mathrm{~M}$$ weak acid $$\mathrm{H} A$$ in a conductivity cell is $$2 \times 10^3 \mathrm{~Ohm}$$. The cell constant of the cell is $$0.78 ~\mathrm{C} \mathrm{~m}^{-1}$$ and $$\lambda_{\mathrm{m}}^{\circ}$$ of acid $$\mathrm{H} A$$ is $$390 \mathrm{~S} \mathrm{~cm}^2 \mathrm{~mol}^{-1}$$. The $$\mathrm{pH}$$ of the solution is

During the electrolysis of brine, by using inert electrodes,

Consider the following 4 electrodes

$$\begin{aligned} & \mathrm{A}: \mathrm{Ag}^{+}(0.0001 \mathrm{M}) / \mathrm{Ag}(s) ; \\ & \mathrm{B}: \mathrm{Ag}^{+}(0.1 \mathrm{M}) / \mathrm{Ag}(s) ; \\ & \mathrm{C}: \mathrm{Ag}^{+}(0.01 \mathrm{M}) / \mathrm{Ag}(s) ; \\ & \mathrm{D}: \mathrm{Ag}^{+}(0.001 \mathrm{M}) / \mathrm{Ag}(s) ; E^{\circ}{ }_{\mathrm{Ag}^{+} / \mathrm{Ag}}=+0.80 \mathrm{~V} \end{aligned}$$

Then reduction potential in volts of the electrodes in the order.

In fuel cells _______ are used as catalysts.

The molar conductivity is maximum for the solution of concentration

For spontaneity of a cell, which is correct?

Specific conductance of $$0.1 \mathrm{~M} \mathrm{~HNO}_3$$ is $$6.3 \times 10^{-2} \mathrm{~ohm}^{-1} \mathrm{~cm}^{-1}$$. The molar conductance of the solution is

Consider the following electrodes

$$\begin{aligned} & P=\mathrm{Zn}^{2+}(0.0001 \mathrm{M}) / \mathrm{Zn}, Q=\mathrm{Zn}^{2+}(0.1 \mathrm{M}) / \mathrm{Zn} \\ & R=\mathrm{Zn}^{2+}(0.01 \mathrm{M}) / \mathrm{Zn}, S=\mathrm{Zn}^{2+}(0.001 \mathrm{M}) / \mathrm{Zn} \end{aligned}$$

$$E^{\circ}(\mathrm{Zn} / \mathrm{Zn}^{2+})=-0.76 \mathrm{~V}$$ electrode potentials of the above electrodes in volts are in the order

The resistance of $$0.01 \mathrm{~m} \mathrm{~KCl}$$ solution at $$298 \mathrm{~K}$$ is $$1500 \Omega$$. If the conductivity of $$0.01 \mathrm{~m} \mathrm{~KCl}$$ solution at $$298 \mathrm{~K}$$ is $$0.1466 \times 10^{-3} \mathrm{~S} \mathrm{~cm}^{-1}$$. The cell constant of the conductivity cell in $$\mathrm{cm}^{-1}$$ is

$$\mathrm{H}_2(g)+2 \mathrm{AgCl}(s) \rightleftharpoons 2 \mathrm{Ag}(s)+2 \mathrm{HCl}(a q)$$

$$E_{\text {cell }}^{\circ}$$ at $$25^{\circ} \mathrm{C}$$ for the cell is $$0.22 \mathrm{~V}$$. The equilibrium constant at $$25^{\circ} \mathrm{C}$$ is

The pair of electrolytes that posses same value for the constant $$(A)$$ in the Debye-Huckel-Onsager equation, $$\Lambda_m=\Lambda_m^{\circ}-A \sqrt{C}$$ is

Given $$E_{F{e^{3 + }}/F{e^{2 + }}}^o = + 0.76\,V$$ and $$E_{\mathrm{I}_2 / \mathrm{I}^{-}}^0=+0.55 \mathrm{~V}$$. The equilibrium constant for the reaction taking place in galvanic cell consisting of above two electrodes is $$\left[\frac{2303 R T}{F}=0.06\right]$$

If an aqueous solution of $$\mathrm{NaF}$$ is electrolysed between inert electrodes, the product obtained at anode is

One litre solution of $$\mathrm{MgCl}_2$$ is electrolysed completely by passing a current of $$1 \mathrm{~A}$$ for $$16 \mathrm{~min} 5 \mathrm{~sec}$$. The original concentration of $$\mathrm{MgCl}_2$$ solution was (Atomic mass of $$\mathrm{Mg}=24$$ )

An aqueous solution of $$\mathrm{CuSO}_4$$ is subjected to electrolysis using inert electrodes. The $$\mathrm{pH}$$ of the solution will

Give $$E_{\mathrm{Mn}^{+7} \mid \mathrm{Mn}^{+2}}^0=1.5 \mathrm{~V}$$ and $$E_{\mathrm{Mn}^{+4}\mid \mathrm{Mn}^{+2}}^0=1.2 \mathrm{~V}$$, then $$E_{\mathrm{Mn}^{+7} \mid \mathrm{Mn}^{+4}}^0$$ is

Addition of excess of $$\mathrm{AgNO}_3$$ to an aqueous solution of 1 mole of $$\mathrm{PdCl}_2 \cdot 4 \mathrm{NH}_3$$ gives 2 moles of $$\mathrm{AgCl}$$. The conductivity of this solution corresponds to

By passing electric current, $\mathrm{NaClO}_3$ is converted in to $\mathrm{NaClO}_4$ according to the following equation

$$ \mathrm{NaClO}_3+\mathrm{H}_2 \mathrm{O} \longrightarrow \mathrm{NaClO}_4+\mathrm{H}_2 $$

How many moles of $\mathrm{NaClO}_4$ will be formed when three Faradays of charges is passed through $\mathrm{NaClO}_3$ ?

The standard reduction potential at 298 K for the following half cell reaction

$$ \begin{aligned} & 2 \mathrm{n}^{2+}(a q)+2 e^{-} \rightarrow \mathrm{Zn}(s) ; E^0=-0.762 \mathrm{~V} \\ & \mathrm{Cr}^{3+}(a q)+3 e^{-} \rightarrow \mathrm{Cr}(s) ; E^0=0.740 \mathrm{~V} \\ & 2 \mathrm{H}^{+}(a q)+2 e^{-} \rightarrow \mathrm{Hz}(g) ; E^0=0.0 \mathrm{~V} \\ & \mathrm{~F}_2(g)+2 e^{-} \rightarrow 2 \mathrm{~F}^{-}(a q) ; E^0=2.87 \mathrm{~V} \end{aligned} $$

Which of the following is strongest reducing agent?

In the electrolysis of aqueous sodium chloride solution, which of the half cell reaction will occur at anode?