Explanation:Acetic acid (CH₃COOH)The percentage composition of CARBON , hydrogen and oxygen PRESENT in acetic acid.➛ FIRST we have to find the molar mass of acetic acid.     Molar mass of CH₃COOH = 12 + 3 + 12 + 16 + 16 + 1     Molar mass of CH₃COOH = 60 gPercentage of carbon:➛ The percentage composition of carbon is GIVEN by,     Percentage composition of carbon = Molar mass of carbon in the compound/Total molar mass of compund × 100➛ Molar mass of carbon = 12 g➛ Substitute the data,    Percentage composition of carbon = 12 × 2 /60 × 100    Percentage composition of carbon = 24/60 × 100   Percentage composition of carbon = 40 %    Percentage composition of hydrogen:➛ Percentage composition of hydrogen = Molar mass of hydrogen in the compound/Total molar mass of compund × 100➛ Molar mass of hydrogen = 1g➛ Substituting the data,     Percentage composition of hyrogen = 4/60 × 100     Percentage composition of hydrogen = 6.67 %     Percentage composition of oxygen:➛Percentage composition of oxygen = Molar mass of oxygen in the compound/Total molar mass of compund × 100➛ Molar mass of oxygen = 16 g➛ Substituting the data,     Percentage composition of oxygen = 16 × 2/60 × 100     Percentage composition of oxygen = 53.33 %