Question

Which contains the greatest mass of oxygen: 0.75 mol of ethanol (C2H5OH), 0.60 mol of formic acid (HCO2H) or 1.0 mol

Answer 1

Answer:

formic acid

Explanation:

(a) 0.75 moles of $C_2H_5OH$

1 mole of $C_2H_5OH$ contains 1 mole of O

so,

0.75 moles of  $C_2H_5OH$ 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 $HCOOH$

1 mole of $HCOOH$ contains 2 moles of O

so,

0.60 moles of  $HCOOH$ 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 $H_2O$

1 mole of $H_2O$ 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.