Question

A sample of crushed rock is found to have 4.81 x10^21 atoms of gold. How many moles of gold are present in this sample?

Answer 1

Answer:

0.8 moles

Explanation:

To find the number of moles in a substance given it's number of entities we use the formula

$n = \frac{N}{L}$

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

We have

$n = \frac{4.81 \times {10}^{23} }{6.02 \times {10}^{23} } = \frac{4.81}{6.02} \\ = 0.799003...$

We have the final answer as

0.8 moles

Hope this helps you