Question

How many atoms of gold (Au) are equal to 212g of gold?

Answer 1

Given :

Mass of gold ( Au ) is 212 gram.

To Find :

Atoms of gold present in 212 gram of gold.

Solution :

Molecular mass of gold is 197 gram.

So, number of moles of gold in 212 gram is :

$n = \dfrac{212}{197} \ moles\\\\n = 1.076 \ moles$

Now, we know 1 mole of any element contains $6.022 \times 10^{23}$ atoms.

So, number of atoms present in 1.076 moles are :

$N = 1.076 \times 6.022\times 10^{23}\\\\N = 6.48 \times 10^{23}$

Hence, this is the required solution.