Question

(a) Calculate the number of electrons in a small, electrically neutral silver pin that has a mass of 7.0 g. Silver has 47 electrons per atom, and its molar mass is 107.87 g/mol.

Answer 1

Answer: The number of electrons in given amount of silver are $1.839\times 10^{24}$

Explanation:

The number of moles is defined as the ratio of the mass of a substance to its molar mass.

The equation used is:

......(1)

We are given:

Mass of silver = 7.0 g

Molar mass of silver = 107.87 g/mol

Putting values in equation 1:

$\text{Moles of silver}=\frac{7.0g}{107.87g/mol}=0.0650 mol$

According to the mole concept:

1 mole of a compound contains $6.022\times 10^{23}$ number of particles.

Number of electrons per atom of silver = 47

So, 0.065 moles of silver will contain = $(0.065\times 6.022\times 10^{23}\times 47)=1.839\times 10^{24}$ number of electrons

Hence, the number of electrons in given amount of silver are $1.839\times 10^{24}$