Overview
This workshop covers how to convert between grams, moles, and atoms in chemistry using molecular weight and Avogadro's number.
Grams to Moles Conversion
- To convert grams to moles, use the molecular weight of the substance (grams per mole).
- Calculate molecular weight by summing atomic masses for each element multiplied by the number of atoms in the compound.
- Set up unit conversion: grams × (1 mole / molecular weight in grams).
- Example: 5 grams of CO₂ × (1 mole / 44.01 g) = 0.11 moles CO₂.
- Example: 6.3 grams of sucrose × (1 mole / 342.3 g) = 0.018 moles sucrose.
Moles to Atoms Conversion
- Use Avogadro's number: 1 mole = 6.022 × 10²³ atoms.
- Set up unit conversion: moles × (6.022 × 10²³ atoms / 1 mole).
- Example: 3 moles of sucrose × (6.022 × 10²³ atoms / 1 mole) = 1.807 × 10²⁴ atoms.
Grams to Atoms Conversion
- First, convert grams to moles using molecular weight.
- Then, convert moles to atoms using Avogadro's number.
- Example (methane): 5 grams CH₄ × (1 mole / 16.04 g) = 0.31 moles CH₄.
- 0.31 moles × (6.022 × 10²³ atoms / 1 mole) = 1.87 × 10²³ atoms.
Key Terms & Definitions
- Molecular Weight — Sum of atomic masses in a compound, used to convert grams to moles.
- Avogadro's Number — 6.022 × 10²³ particles (atoms, molecules) per mole.
- Mole — Unit representing 6.022 × 10²³ particles of a substance.
Action Items / Next Steps
- Practice converting between grams, moles, and atoms using the outlined processes.
- Review calculation of molecular weights for other compounds.