Question

a) What type of a battery is the lead storage battery? Write the anode and the cathode reactions and the overall reaction occurring in a lead storage battery when current is drawn from it.

(b) In the button cell, widely used in watches, the following reaction takes place

$Zn left parenthesis straight s right parenthesis space plus Ag subscript 2 straight O space plus straight H subscript 2 straight O space rightwards arrow Zn to the power of 2 plus end exponent left parenthesis aq right parenthesis space plus 2 Ag left parenthesis straight s right parenthesis space plus 2 OH to the power of minus left parenthesis aq right parenthesis$

Determine E° and G° for the reaction $left parenthesis given space straight E subscript bevelled Ag to the power of plus over Ag end subscript superscript 0 space equals space plus 0.80 straight V comma space straight E subscript bevelled Zn to the power of 2 plus end exponent over Zn end subscript superscript 0 space equals negative 0.76 straight V right parenthesis space$

Solution

A lead storage battery has a secondary cell. Thus, it can be recharged by passing direct current through it. Therefore, it can be reused. It is used in automobiles.

In a lead storage cell, the anode is made of spongy lead and the cathode is a grid of lead packed with lead dioxide. The electrolyte used is H₂SO₄.

$At space anode colon space Pb space plus SO subscript 4 superscript 2 minus end superscript space rightwards arrow PbSO subscript 4 space plus 2 straight e to the power of minus At space cathode colon PbO subscript 2 space plus SO subscript 4 superscript 2 minus end superscript space plus 4 straight H to the power of plus plus 2 straight e to the power of minus rightwards arrow PbSO subscript 4 space plus 2 straight H subscript 2 straight O Overall space cell space reaction colon Pb space plus PbO subscript 2 space plus 4 straight H to the power of plus space plus SO subscript 4 superscript 2 minus end superscript space rightwards arrow space 2 PbSO subscript 4 space plus 2 straight H subscript 2 straight O left parenthesis straight b right parenthesis space From space the space given space reaction comma space it space is space known space that space zinc space is space oxidized space and space silver space is space reduced space in space the space button space cell. space space The space reactions space occurring space at space the space anode space and space cathode space are space minus Anode colon space Zn left parenthesis straight s right parenthesis space space rightwards arrow Zn to the power of 2 plus end exponent left parenthesis aq right parenthesis space plus 2 straight e to the power of minus Cathode colon space Ag subscript 2 straight O space left parenthesis straight s right parenthesis space plus straight H subscript 2 straight O space left parenthesis straight l right parenthesis space space plus 2 straight e to the power of minus space rightwards arrow 2 Ag left parenthesis straight s right parenthesis space plus 2 OH to the power of minus Now comma straight E subscript cell superscript 0 space equals straight E subscript cathode superscript 0 minus straight E subscript anode superscript 0 equals space straight E subscript bevelled Ag to the power of plus over Ag end subscript superscript 0 space minus space straight E subscript bevelled Zn to the power of 2 plus end exponent over Zn end subscript superscript 0 equals 0.80 minus left parenthesis negative 0.76 right parenthesis We space know space that space increment subscript straight r straight G to the power of 0 space equals negative nE to the power of 0 straight F Here comma straight n equals 2 straight F equals 96500 straight C space mol to the power of negative 1 end exponent increment subscript straight r straight G to the power of 0 space equals negative 2 space straight x space 1.56 space straight x space 96500 space straight J space mol to the power of negative 1 end exponent equals space minus 301080 space straight J space mol to the power of negative 1 end exponent$

For Daily Free Study Material Join wiredfaculty

Electrochemistry

Some More Questions From Electrochemistry Chapter

Why does the conductivity of a solution decrease with dilution?

Suggest a way to determine the Λ°_m value of water.

The molar conductivity of 0.025 mol L^–1methanoic acid is 46.1 S cm² mol^–1. Calculate its degree of dissociation and dissociation constant. Give λ°(H⁺) = 349.6 S cm²mol^–1 and λ° (HCOO^– ) = 54.6 s cm² mol^–1.

If the current of 0.5 ampere flows through a metallic wire for 2 hours, then how many electrons flow through the wire?

Suggest a list of metals that are extracted electrolytically.

Consider the reaction: Cr₂O₇^2– + 14H⁺ + 6e- → 2Cr³⁺ + 8H₂O
What is the quantity of electricity in coulombs needed to reduce 1 mol of Cr₂O₇^2-?

Write the chemistry of recharging the lead storage battery, highlighting all the materials that are involved during recharging.

Mock Test Series

NCERT Sample Papers

Entrance Exams Preparation

Phone Number

Email Address

Loaction