Answer: The number of moles of sodium chloride are 0.40 moles
Step-by-step explanation:
We are given:
Number of formula units =

According to mole concept:
number of formula units are contained in 1 mole of a substance
So,
number of formula units will be contained in
moles of sodium chloride
Hence, the number of moles of sodium chloride are 0.40 moles