Calculate the percent composition of the elements in each compound.
MgSO4
C6H12O6
Question 2 options:
the element that comprises approximately 20.2% of the compound.
the element that comprises 40% of the compound.
1.
The C in C6H12O6
2.
The Mg in MgSO4
For MgSO4:
Mg: 1 atom x 24.31 g/mol = 24.31 g/mol
S: 1 atom x 32.07 g/mol = 32.07 g/mol
O: 4 atoms x 16.00 g/mol = 64.00 g/mol
Total molecular weight = 24.31 + 32.07 + 64.00 = 120.38 g/mol
Percent composition:
Mg: (24.31 g/mol / 120.38 g/mol) x 100% = 20.18%
S: (32.07 g/mol / 120.38 g/mol) x 100% = 26.66%
O: (64.00 g/mol / 120.38 g/mol) x 100% = 53.16%
For C6H12O6:
C: 6 atoms x 12.01 g/mol = 72.06 g/mol
H: 12 atoms x 1.01 g/mol = 12.12 g/mol
O: 6 atoms x 16.00 g/mol = 96.00 g/mol
Total molecular weight = 72.06 + 12.12 + 96.00 = 180.18 g/mol
Percent composition:
C: (72.06 g/mol / 180.18 g/mol) x 100% = 39.98%
H: (12.12 g/mol / 180.18 g/mol) x 100% = 6.73%
O: (96.00 g/mol / 180.18 g/mol) x 100% = 53.29%
For the element that comprises approximately 20.2% of the compound:
This would be Mg in MgSO4, which has a percent composition of 20.18%.
For the element that comprises 40% of the compound:
This would be O in C6H12O6, which has a percent composition of 53.29%.