Question

How many electron are present in 19.7kg of gold

Answer 1

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

25

Explanation:

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

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

Molar mass

Given 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}=100molMoles of gold=

197g/mol

19700g

=100mol

According to mole concept:

1 mole of an element contains 6.022\times 10^{23}6.022×10

23

number of atoms.

So, 100 moles of gold will contain 100\times 6.022\times 10^{23}=6.022\times 10^{25}100×6.022×10

23

=6.022×10

25

number of atoms.

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

25