an organic compound was analyzed and found to contain 70.6% carbon, 5.9% hydrogen, and 23.5% oxygen by mass. additionally, the molar mass of the compound was experimentally determined to be 136 g/mole. what is the molecular formula for the compound? how many grams of mgcl 2 would be required to prepare 250 ml of a 0.8 m solution of that solute in water? please report your answer to two digits after the decimal place.