First we calculate the mass of carbon, hydrogen and oxygen.
Mass of Carbon;
Molar mass of CO₂ is 44.009g/mol and molar mass of C = 12.011 g/mol
Mass of Carbon in 14.08g CO2₂ = 12.011/44.009 x 14.08 = 3.84
Mass Hydrogen;
Molar mass H₂O is 18.0015g/mol and molar mass of H is 1.008and H₂ = 2.016
Mass Hydrogen in 4.32g of H₂O = 2.016/18.0015 x 4.32 = 0.48
Mass of Oxygen
= total mas of tartaric acid – (mass of carbon + mass of hydrogen) = 12.01 -
(3.84+0.48) = 7.69
Now divide carbon, hydrogen and oxygen through
their respective atomic masses:
C = 3.84/12.011 = 0.32
H = 0.48/1.008 = 0.48
O = 7.69/15.999 = 0.48
Now divide by smallest:
C = 0.32/0.32 = 1
H = 0.48/0.32 = 1.5
O = 0.48/0.32 = 1.5
multiply by 2 to get whole integers:
C = 1 x 2 = 2
H= 1.5 x 2 = 3
O= 1.5 x 2 = 3
Thus, the Empirical formula of tartaric acid =
C₂H₃O₃
