Question

calculate the mass per cent of carbon and hydrogen present in C2H5OH​

Answer 1

Percentage composition = (Mass of the element) ×100/ (Molar mass of the compound )

Mass of Carbon = 12

Mass of Hydrogen (H) = 1

Mass of Oxygen (O) = 16

Molar mass of compound = [ (2×12) + 5 + 16 + 1 ]

= ( 46 + 5 + 16 + 1)

= 46 //

% composition of Carbon

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= ( 24 × 100) / 46

= 52.17

= 52.2 % //

% composition of Hydrogen

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= (6 × 100) / 46

= 13.04 % //

% composition of oxygen

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= ( 16 × 100) / 46

= 34.78 % //