Respuesta :
40g C
6.7g H
53.3g O
--------------
100g total
Divide each element by its molar mass
40g C x 1mol / 12.01g = 3.33mol C
6.7g H x 1mol / 1.01g = 6.09mol H
53.3g O x 1mol/ 16.00g = 3.33mol O
Divide each mole number by the smallest # of moles. In this case, 3.33 is the smallest.
3.33mol C / 3.33mol = 1 C
6.09mol H / 3.33mol = 1.83 H
3.33mol O / 3.33mol = 1 O
Empirical Formula = CH2O
The empirical formula is CH2O
calculation
step 1: calculate the moles of each element present in the compound.
moles = % composition / molar mass
- from periodic table the molar mass for carbon =12 g/mol ,
for hydrogen = 1 g/mol
for oxygen = 16 g/mol
- moles is therefore
for Carbon (C) = 40 /12 = 3.33 moles
for hydrogen (H) = 6.7 /1= 6.70 moles
for oxygen(O) = 53.3 / 16=3.33 moles
Step 2 : find the mole ratio of C:H:O by diving each mole by smallest mole ( 3.33 moles)
that is carbon (C) = 3.33/3.33 =1
Hydrogen(H) = 6.70 / 3.33=2
Oxygen(O) = 3.33/3.33 =1
Therefore the empirical formula = CH2O