Chapter 3 Electrochemistry, Chemistry class 12 Chapter 3 Electrochemistry Chemistry, Class 12 | Page 14

Measurement of resistance of a solution of an electrolyte
A man touching the electric pole with a metal rod will get an electric shock because metal rod is a conductor whereas a man touching the same with a wooden plank will be safe because wood is an insulator .
Semiconductors :
o Solids with conductivities in the intermediate range from 10 – 6 to 104 ohm – 1 m – 1 . o
For example , Gallium , Germanium , Silicon
Measurement of resistance of a solution of an electrolyte
o
In the formula
o l / A is called cell constant denoted by the symbol , G ’.
o The cell constant depends on the distance between the electrodes ( l ) and their area of cross-section ( A ). o
It is determined by measuringthe resistance of the cell containing a solution of known conductivity .
PROBLEM :
THE RESISTANCE OF A CONDUCTIVITY CELL CONTAINING 0.001M KCL SOLUTION AT 298 K IS 1500 Ω . WHAT IS THE CELL CONSTANT IF