A compound contains 9.50 moles of carbon, 9.60 moles of hydrogen and 2.38 moles of sulfur. The molar mass of the compound is 168 grams per mole. What is the empirical and molecular formula of the compound?

the catch is that the top numbers are atomic masses the bottom numbers are the numbers of protons and electrons in an uncharged atom. they are the number of that atoms as you would find them on the periodic table. further, the numbers on the left are used to determine the missing numbers on the right

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer

The teacher is mostly talking about the distillation of a mixture