(a) Calculate the mass of Ag deposited at cathode when a current of 2 amperes was passed through a solution of `AgNO_3` for 15 minutes.
[Given : Molar mass of Ag = 108 g `mol^(-1)`, 1 F = 96500 C `mol^(-1)`]
(b) Define fuel cell.

Explanation

(a) Here, `t = 15 xx 60 =900` seconds, current =2 amperes
`therefore` Charge = Current `xx` time
`=2 xx 900 = 1800 C`
`Ag^(+) + e^(-) to Ag(s)`
We require 1F or 96500 C to deposit one mole or 108 g of Ag.
Mass deposited with 1800 C `=108/96500 xx 1800 g = 2.0145 g`
(6) Fuel cell : 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.