The liquid contains 66.6c, 11.2% H and 22.2% 0. What is its molecular formula? How do i figure that?

Answer 1

Assume you have 100 grams of the stuff. then you have
66.6 g C, or xxxx moles
11.2 g H, or yyyyy moles
22.2 g O, or zzzzz moles

then examine xxxx, yyyy, zzzz. That is the mole ratio in the formula. Reduce it to a whole number ratio. Often, you can get it by dividing all three by the lowest.