Batteries

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Batteries: Overview

This topic covers concepts, such as, Hydrogen-Oxygen Fuel Cell, Advantage of Hydrogen-Oxygen Fuel Cell, Nickel-Cadmium Storage Cell & Calculation of Percentage Efficiency of a Fuel Cell etc.

Important Questions on Batteries

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Chemistry>Electrochemistry>Batteries> Q 1

Nickel-cadmium cell is:

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Chemistry>Electrochemistry>Batteries> Q 2

The type of cell in a lead storage battery is:

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Chemistry>Electrochemistry>Batteries> Q 3

The conductance of metallic substance is because of

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Chemistry>Electrochemistry>Batteries> Q 4

The equilibrium constant for the reaction would be:

{Fe}_{(a q)}^{2 +} + {Ce}_{(a q)}^{3 +} ⇌ {Ce}_{(a q)}^{2 +} + {Fe}_{(a q)}^{3 +}

Given that

E_{{Ce}^{3 +} / {Ce}^{2 +}}^{o} = 1.44 V, E_{{Fe}^{3 +} / {Fe}^{2 +}}^{o} = 0.68 V

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Chemistry>Electrochemistry>Batteries> Q 5

During the discharge of a lead storage battery, the density of sulphuric acid fell from 1.294 to 1.139 $g m l^{- 1} .$ Sulphuric acid of density 1.294 $g m l^{- 1} i s 39 %$ by weight and that of 1.139 $g m l^{- 1} i s 20 % H_{2} S O_{4}$ by weight. The battery holds 3.5 litres of the acid and the volume remained practically constant during the discharge.

The number of ampere-hours for which the battery must have been used. The charging and discharging reactions are:

Anode:

$Pb (s) + {SO}_{4}^{2 -} (aq) ⇌ {PbSO}_{4} (s) + 2 e^{-} (discharging)$

Cathode:

${PbO}_{2} (s) + 4 H^{+} (aq) + {SO}_{4}^{2 -} (aq) + 2 e^{-} ⇌ {PbSO}_{4} (s) + 2 H_{2} O (l) (discharging)$

Note: Both the reactions take place at the anode and cathode respectively during discharge. Both reaction get reverse during charging.

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Chemistry>Electrochemistry>Batteries> Q 6

A cell, $A g | A g^{+} ∥ C u^{2 +} | C u,$ initially contains 1 M $A g^{+}$ and 1 $M C u^{2 +}$ ions.

Calculate the change in the cell potential after the passage of 9.65 A of current for 1 h.

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Chemistry>Electrochemistry>Batteries> Q 7

For the electrochemical cell, $(M | M^{+}) ∥ (X^{-} | X), E ° (M^{+} / M) = 0 .44 V and E^{o} (X / X^{-}) = 0 .33 V .$

From this data one can deduce that:

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Chemistry>Electrochemistry>Batteries> Q 8

In hydrogen-oxygen fuel cell, combustion of hydrogen occurs to –

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Chemistry>Electrochemistry>Batteries> Q 9

Button cells are used in portable electronic devices.

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Chemistry>Electrochemistry>Batteries> Q 10

In the silver oxide button cell, zinc act as a cathode.

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Chemistry>Electrochemistry>Batteries> Q 11

The biggest difference between the two is that a battery stores energy, while a fuel cell generates energy by converting available _____.

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Chemistry>Electrochemistry>Batteries> Q 12

Which of the following is correct labelling of lead storage battery:

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Chemistry>Electrochemistry>Batteries> Q 13

In hydrogen-oxygen fuel cell, the carbon rods are immersed in hot aqueous solution of:

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Chemistry>Electrochemistry>Batteries> Q 14

Which of the following are correctly label for $H_{2}, O_{2}$ fuel cell

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Chemistry>Electrochemistry>Batteries> Q 15

Which of the following is correct labelling of $H_{2}, O_{2}$ fuel cell:

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Chemistry>Electrochemistry>Batteries> Q 16

Galvanic cells that are designed to convert the energy of combustion of fuels like hydrogen, methane, methanol, etc. directly into electrical energy are called fuel cells.

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Chemistry>Electrochemistry>Batteries> Q 17

The anode reaction which is taking place in nickel- cadmium battery can be represented by which of the following equation?

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Chemistry>Electrochemistry>Batteries> Q 18

Define fuel cell and write its two advantages.

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Chemistry>Electrochemistry>Batteries> Q 19

When $Pb$ -storage battery is discharged, then: