Answer: 0.25 moles O in the sample
Explanation:
0.250 moles: C = (0.250 moles)*(12 g/mole) = 3 grams C
0.500 moles H: H = (0.500 moles)*(1 g/mole) = 0.5 grams H
Total mass is 7.5g
Subtract C and H to find grams O (7.5 g -(3 grams C + 0.5 grams H) = 4.0 grams O. Molar mass of O is 16 grams/mole.
Moles O = 0.25 O in the sample
The empirical formula is C1H2O1, possibly formalhyde.
