What is the mass in grams of 1.50 X 1023 molecules of NaOH?
a. 10.0 g
b. 20.0 g
c. 30.0 g
d. 40.0 g
e. 60.0 g

a. 10.0 g

Explanation:

The molar mass of NaOH is 39.997 grams which was calculated by adding the molar mass of Sodium, Oxygen, and Hydrogen . But before we do anything with this number we must first convert molecules to moles. We can do this by dividing by Avogadro's number or  ( moles). We then convert moles to grams by multiplying by the molar mass of NaOH, ( grams). This is almost exactly 10 and the margin of error is likely due to the original numbers not being precise enough.