Question

Complete the following table by replacing question marks with the correct numbers: (Note: Each horizontal row is a separate example, so in row #1, 175.32 grams of NaCl is how many moles of NaCl and how many molecules of NaCl does it contain?)

Grams NaCl Moles NaCl # Molecules NaCl
175.32 ? ?
? 0.333 ?
? ? 6.02x10^23

Answer 1

NaCl is 23 + 35.5 = 58.5 grams / mol
so
175.32 grams + 1 mol/58.5 grams = 3 moles of NaCl
and
3 moles * 6*10^23 molecules/mole = 1.8*10^24 molecules