The magnitude of charge on an electron is `1.603 xx 10^(-19)C`. The value of the faraday constant, `F`, is

Options

A. `96.5 C mol^(-1)`
B. `96,500 C mol^(-1)`
C. `9.65 C mol^(-1)`
D. `965, 000 C mol^(-1)`

Answer

B

Explanation

`F`. The faraday (or Faraday constant) is equivalent to the electric charge on one mole of electrons. Therefore, `1 F` is called `1` mole of electricity. The charge on a single electron is `1.602 xx 10^-(19)C`. If we multify this charge by Avogardo's constant, we get
`(1.602 xx 10^(-19)(C)/(e^(-)))(6.0222 xx 10^(23)(e^(-))/(mol e^(-)))`
`= 9.6472 xx 10^(4) (C)/(mol e^(-))`
In our calculations, we will round the value of `F` to three significant figures:
`F = 96,500 C//mol e^(-)`
A unit other than the mole is more convenient when we are dealing with electrons. When we talk about "a mole" we usuallly indicate the mass of the substance: `1` mol of `Na` is `23 g` and of `Cl_(2)` is `71 g`.
However, it is more convenient to express a mole of electrons as charge in coulombs, rather than as mass in grams because the mass of electrons is so small. We usually express `1` mol electrons as `96,500 C` of charge.