Question

19.7Kg of gold was recovered from a smuggler. How many atoms of gold were recovered? ( at. mass. of Au = 197 )

Answer 1

hey
total atoms will be:-
19700/197 × Avagadro number

Answer 2

Answer: The number of atoms of gold that was recovered is $6.022\times 10^{25}$

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Given mass of gold = 19.7 Kg = 19700 g     (Conversion factor: 1 kg = 1000 g)

Molar mass of gold = 197 g/mol

Putting values in above equation, we get:

$\text{Moles of gold}=\frac{19700g}{197g/mol}=100mol$

According to mole concept:

1 mole of an element contains $6.022\times 10^{23}$ number of atoms.

So, 100 moles of gold will contain $100\times 6.022\times 10^{23}=6.022\times 10^{25}$ number of atoms.

Hence, the number of atoms of gold that was recovered is $6.022\times 10^{25}$