Which contains the greatest mass of oxygen: 0.75 mol of ethanol (c2h5oh), 0.60 mol of formic acid (hco2h) or 1.0 mol
of water (h2o) ? explain why.

formic acid

Explanation:

(a) 0.75 moles of

1 mole of contains 1 mole of O

so,

0.75 moles of   contains 0.75 mole of O

Molar mass of O = 16 g/mol

Mass = moles* Molar mass = 0.75 moles × 16 g/mol = 12 g

(b) 0.60 moles of

1 mole of contains 2 moles of O

so,

0.60 moles of   contains 0.60*2 mole of O

Moles of O = 1.2

Molar mass of O = 16 g/mol

Mass = moles* Molar mass = 1.2 moles × 16 g/mol = 19.2 g

(c) 1 mole of

1 mole of contains 1 mole of O

Molar mass of O = 16 g/mol

Mass = moles* Molar mass = 1 mole × 16 g/mol = 16 g

Greatest mass = 19.2 g = formic acid.