Asalt crystal has a mass of 0.15 mg. how many nacl formula units does it contain?

2.56×10^-6 moles

Explanation:

Number of formula units is the same as the number if moles of NaCl present.

Number of moles= mass/ molar mass

Molar mass of NaCl= (23+35.5)= 58.5gmol-1

Given mass of NaCl= 0.15×10^-3g

Number of moles= 0.15×10^-3/58.5

Number of moles = 2.56×10^-6 moles