Final answer:
The formula weight of ethanol, C₂H₅OH, is calculated by adding the atomic masses of its constituent elements: 24.02 g/mol for carbon, 6.048 g/mol for hydrogen, and 16.00 g/mol for oxygen, equaling 46.068 g/mol, which is typically rounded to 46 g/mol.
Step-by-step explanation:
To calculate the formula weight of ethanol, C₂H₅OH, we need to consider the atomic masses of the elements that constitute the ethanol molecule. The molecular formula of ethanol can be expressed as C₂H₅OH. Thus, we can calculate the formula weight by summing up the atomic masses of 2 carbon (C) atoms, 6 hydrogen (H) atoms, and 1 oxygen (O) atom:
- Carbon (C): 12.01 g/mol × 2 = 24.02 g/mol
- Hydrogen (H): 1.008 g/mol × 6 = 6.048 g/mol
- Oxygen (O): 16.00 g/mol
The formula weight of ethanol is therefore:
24.02 g/mol (Carbon) + 6.048 g/mol (Hydrogen) + 16.00 g/mol (Oxygen) = 46.068 g/mol
This value is generally rounded to 46 g/mol for practical purposes.