Uploaded August 2025 | Updated September 2026, 2 weeks ago
Calculating Empirical and Molecular Formulas
Dr. DeBacco
Empirical Formula
Shows the smallest whole number ratio of atoms in a compound.
Ex. Empirical formula = CH2O
Molecular formula = C6H12O6
To determine empirical formula from % composition:
Assume you have 100.0 g of the sample
Calculate the % composition of the sample
Convert mass to moles of each element in the compound
Divide moles of each element by the smallest number to find ratio
Calculating: Empirical Formula
Calculating: Molecular Formula
Molecular Formula Calculations
Example
Link to Lecture Slides: drive.google.com/file/d/1uvsYMdIInHwjY8boPvpaO1DHTh9_ZxAE/view?usp=drive_link
*Due to the description character limit the full work cited for "Calculating Empirical and Molecular Formulas" can be viewed at... docs.google.com/document/d/1ZAUDlsamQ8kUbaa6GwnZSkAz_UFnWW6A/edit?usp=drive_link&ouid=104237452697237972847&rtpof=true&sd=true
Calculating Empirical and Molecular Formulas
Dr. DeBacco
Empirical Formula
Shows the smallest whole number ratio of atoms in a compound.
Ex. Empirical formula = CH2O
Molecular formula = C6H12O6
To determine empirical formula from % composition:
Assume you have 100.0 g of the sample
Calculate the % composition of the sample
Convert mass to moles of each element in the compound
Divide moles of each element by the smallest number to find ratio
Calculating: Empirical Formula
Calculating: Molecular Formula
Molecular Formula Calculations
Example
Link to Lecture Slides: drive.google.com/file/d/1uvsYMdIInHwjY8boPvpaO1DHTh9_ZxAE/view?usp=drive_link
*Due to the description character limit the full work cited for "Calculating Empirical and Molecular Formulas" can be viewed at... docs.google.com/document/d/1ZAUDlsamQ8kUbaa6GwnZSkAz_UFnWW6A/edit?usp=drive_link&ouid=104237452697237972847&rtpof=true&sd=true










