How does the pH of an aqueous sodium chloride solution change when it is electrolysed using inert platinum electrodes?

1. It increases
2. It decreases
3. It remains unchanged
4. It initially increases and then decreases

The quantity of electricity required to reduce 12.3 g of nitrobenzene to aniline with 50 % current efficiency is:

1. 1 F

2. 0.6 F

3. 0.5 F

4. 1.2 F

Electrolysis of hot aqueous solution of NaCl gives NaClO₄ as-

$\mathrm{NaCl}<mspace\; width="1em"></mspace>+\hspace{0.17em}4{\mathrm{H}}_2\mathrm{O}<mspace\; width="1em"></mspace>\stackrel{<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>}{\to }{\mathrm{NaClO}}_4<mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>4{\mathrm{H}}_2$

How many faraday are required to obtain 1000 g of sodium perchlorate ?

(1) 66 F

(2) 122.5 F

(3) 15.13 F

(4) 1.86 F

A button cell used in watches functions as following

Zn(s) + Ag₂O(s) + H₂O (l) $\rightleftharpoons$2Ag(s) + Zn²⁺(aq) + 2OH^-(aq)

If half cell potentials are

$$\begin{gathered} {{\mathrm{Zn}}^{2+}}_{\left(\mathrm{aq}\right)}<mspace\; width="1em"></mspace>+\hspace{0.17em}2{\mathrm{e}}^{-}<mspace\; width="1em"></mspace>\to <mspace\; width="1em"></mspace>{\mathrm{Zn}}_{\left(\mathrm{x}\right)};<mspace\; width="1em"></mspace>{\mathrm{E}}^{\mathrm{o}}<mspace\; width="1em"></mspace>=<mspace\; width="1em"></mspace>-0.76\mathrm{V} \\ {\mathrm{Ag}}_2{\mathrm{O}}_{\left(\mathrm{s}\right)}<mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>{\mathrm{H}}_2{\mathrm{O}}_{\left(\mathrm{l}\right)}<mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>2{\mathrm{e}}^{-}<mspace\; width="1em"></mspace>\to <mspace\; width="1em"></mspace>2{\mathrm{Ag}}_{\left(\mathrm{s}\right)}<mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace>2{{\mathrm{OH}}^{-}}_{\left(\mathrm{aq}\right)};<mspace\; width="1em"></mspace> \\ {\mathrm{E}}^{\mathrm{o}}<mspace\; width="1em"></mspace>=<mspace\; width="1em"></mspace>0.34\mathrm{V} \end{gathered}$$

The cell potential will be

1. 0.84 V

2. 1.34 V

3. 1.10 V

4. 0.42 V

Limiting molar conductivity of NH₄OH (i.e Åm(NH₄OH)) is equal to:-

1. Å_m (NH₄Cl)+Å_m(NaCl)-Å_m(NaOH) 

2. Å_m(NaOH)+Å_m(NaCl)-Å_m(NH₄Cl)

3. Å_m(NH₄OH)+Å_m(NH₄Cl)-Å_m(HCl)

4. Å(NH₄Cl)+Å(NaOH)-Å(NaCl)

The efficiency of a fuel cell is given by:

$\left(\mathrm{a}\right)<mspace\; width="1em"></mspace>∆\mathrm{H}/∆\mathrm{G}<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>\left(\mathrm{b}\right)<mspace\; width="1em"></mspace>∆\mathrm{G}/∆\mathrm{S}$
$\left(\mathrm{c}\right)<mspace\; width="1em"></mspace>∆\mathrm{G}/∆\mathrm{H}<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>\left(\mathrm{d}\right)<mspace\; width="1em"></mspace>∆\mathrm{S}/∆\mathrm{G}$

For the hypothetical electrochemical cell given below:

A | A⁺(x M) || B⁺(y M) | B .

The measured cell emf is +0.20 V. Find the overall cell reaction.

1. A⁺ + B → A + B⁺

2.  A⁺ + e^- →  A ; B⁺ + e^- → B

3.  The cell reaction cannot be predicted

4.  A + B⁺ → A⁺ + B

Based on the given data, what is the value of the molar conductivity at infinite dilution (Λm^∞) for SrCl₂ in water at 25°C?

1. 270

2. 260

3. 250

4. 255

During electrolysis of conc. H₂SO₄, perdisulphuric acid (H₂S₂O₈), and O₂
form in equimolar amount. The amount of H₂ that will form simultaneously will be : 

1. Thrice that of O₂ in moles.

2. Twice that of O₂ in moles.

3. Equal to that of O₂ in moles.

4. Half of that of O₂ in moles.

What happens to the voltage in a galvanic cell when the salt bridge is removed?

1. The voltage drops to zero.
2. The voltage remains the same.
3. The voltage gradually increases.
4. The voltage rapidly increases.