What is the molecular formula of the compound ch2 with molar mass = 42.0 g/mol? c4h8 c3h6 c2h4 c2h18

C3H6 because the molar mass of CH2 is 14 g/mol, but to get how many moles it takes to get to 42 g/mol, you need to divide 42 by 14 and that gets you 3 moles.

CH2

Explanation:

i just did it with the first answer that was here and it said it was wrong on edgenuity. so if your on edge. i hope this helps