To calculate the percent composition by mass of each element in glucose (C6H12O6), you need to determine the mass of each element in one mole of the compound, the total molar mass of the compound, and then use these values to calculate the percentage.
Calculating Percent Composition by Mass
Here’s a detailed breakdown of the calculation:
Step 1: Determine the Molar Mass of Glucose
- The molar mass of carbon (C) is approximately 12 g/mol.
- The molar mass of hydrogen (H) is approximately 1 g/mol.
- The molar mass of oxygen (O) is approximately 16 g/mol.
- Glucose (C6H12O6) has 6 carbon atoms, 12 hydrogen atoms, and 6 oxygen atoms.
- According to the provided reference, the molecular mass of glucose is calculated as: (6 × 12) + (12 × 1) + (6 × 16) = 72 + 12 + 96 = 180 g/mol.
Step 2: Calculate the Mass Contribution of Each Element
- Carbon (C): 6 atoms × 12 g/mol = 72 g/mol
- Hydrogen (H): 12 atoms × 1 g/mol = 12 g/mol
- Oxygen (O): 6 atoms × 16 g/mol = 96 g/mol
Step 3: Calculate the Percent Composition of Each Element
The percent composition is calculated using the following formula:
% Element = (Mass of the element / Molar mass of compound) × 100
- Percent Carbon (%C): (72 g/mol / 180 g/mol) × 100 = 40%
- Percent Hydrogen (%H): (12 g/mol / 180 g/mol) × 100 = 6.66%
- Percent Oxygen (%O): (96 g/mol / 180 g/mol) × 100 = 53.33%
Summary in a Table
| Element | Mass Contribution (g/mol) | Percent Composition (%) |
|---|---|---|
| Carbon (C) | 72 | 40.00% |
| Hydrogen (H) | 12 | 6.66% |
| Oxygen (O) | 96 | 53.33% |
Conclusion
The percent composition by mass of each element in glucose (C6H12O6) is approximately: 40% carbon, 6.66% hydrogen, and 53.33% oxygen. These values are derived from the molar masses of the individual elements and the total molar mass of the glucose molecule, as shown in the provided reference.
