Question

Define the following :
(i) Molar conductivity
(ii) Fuel cell
(b) The molar conductivity of a 1.5 M solution of an electrolyte is found to be `138.9" S Cm"^(2)"mol"^(-1)`. Calculate the conductivity of the solution.

Answer 1

Molar conductivity `(^^_(m))` : Molar conductivity of a solution is a conductance of all the ions produced from one mole of the electrolyte dissolved in `Vcm^(3)` of the solution when the electrodes are one cm apart and the area of the electrodes is so large that the whole of the solution is contained between them.
`^^_(m)=(K_(c)xx1,000)/("Molarity")" "[K_(c)rarr"Specific conductivity"]`
(ii) Fual cell : A device in which the heat produced as a result of the combustion of fuel (like `H_(2)-O_(2))` is converted into electricity is called fuel cell.
Molarity = 1.5 M, `^^_(m)=138.9Scm^(2)//mol`
`^^_(m)=(K_(c)xx1,000)/(M)" "rArr" "138.9=(K_(c)xx1,000)/(1.5)`
`rArr" "K_(c)=(138.9xx1.5)/(1,000)=0.208S//cm`