Determine the amu of each element in the compound (periodic table).
Multiply the amu by the element's subscript in the formula to determine the mass of the element in that compound.
Determine the molar mass of the compound (sum the masses of each element).
Divide each element's mass by the compound's molar mass, then multiply by 100.
Rounding - generally, round the percent composition to the nearest hundredth.
Directions - determine the percent composition of each element in the following compounds. Do not forget to include the correct unit for each calculation (grams - g, percent - %)
Question 1
1.
Na3PO4
Molar Mass of compound = _______
Percent Compositions:
Na = _______
P = _______
O = _______
Do not forget to include the correct unit for each calculation (grams - g, percent - %)
Question 2
2.
H2O2
Molar mass = _______
Percent Compositions:
H = _______
O = _______
Do not forget to include the correct unit for each calculation (grams - g, percent - %)
Question 3
3.
CO2
Molar Mass of Compound = _______
Percent Compositions:
C = _______
O = _______
Question 4
4.
C6H12O6
Molar Mass of Compound = _______
Percent Compositions:
C = _______
H = _______
O = _______
Question 5
5.
(NH4)2SO4
Molar Mass of Compound = _______
Percent Compositions:
N = _______
H = _______
S = _______
O = _______
Question 6
6.
NaClO
Molar Mass of Compound = _______
Percent Compositions:
Na = _______
Cl = _______
O = _______
Question 7
7.
MgSO4
Molar Mass of compound = _______
Percent Compositions:
Mg - _______
S =_______
O =_______
Question 8
8.
(NH2)2CO
Molar Mass of Compound = _______
Percent Compositions:
N = _______
H = _______
C = _______
O = _______
Question 9
9.
C10H14N2
Molar Mass of Compound = _______
Percent Compositions:
C = _______
H = _______
N = _______
Question 10
10.
CaSO4. 2 H2O (hydrated compound)
Molar Mass of Compound = _______
Percent Compositions:
Ca = _______
S = _______
O = _______
H =_______
Now that you have completed this assignment, move on to this: