Answer:

Step-by-step explanation:
To find the number of moles in a substance given it's number of entities we use the formula

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
From the question
N = 7.30 × 10²³ NaCl molecules

We have the final answer as
1.213 moles