How many Faradays of electricity are required to deposit 10 g of calcium from molten calcium chloride using inert electrodes ?
( molar mass of calcium = `40 g mol^(-1)`)

Options

A. 0.5 F
B. 1F
C. 0.25 F
D. 2F

Answer

A

Explanation

2 moles of electrons are required to deposit 1 mole of calcium.
Mass of calcium deposited = 10g,
Molar mass of calcium = 40 g `mol^(-1)`
`therefore` No of moles = `10/(40 g "mol"^(-1)) = 0.25` mol
2F are required for 1 mole of calcium
xF are required for 0.25 mole of calcium
`therefore x = 0.25 xx 2 = 0.5 F`