Summary
The mole is a unit used to express the amount of a substance, defined by the number of entities in 12 grams of carbon-12, approximately 6.02 x 10^23 entities per mole. The molar mass is the mass of one mole of a substance in grams, used to convert between moles and grams.
- Mole — a unit of measurement for the amount of a substance Example: One mole of carbon-12 weighs 12 grams.
- Avogadro's constant — the number of entities in a mole Example: Approximately 6.02 x 10^23 entities per mole.
- Molar mass — the mass of one mole of a substance in grams Example: The molar mass of water (H2O) is 18.015 g/mol.
Exam Tips
Key Definitions to Remember
- The mole is a unit of measurement for the amount of a substance.
- Avogadro's constant is approximately 6.02 x 10^23 entities per mole.
- Molar mass is the mass of one mole of a substance in grams.
Common Confusions
- Confusing the mole with molar mass.
- Misunderstanding Avogadro's constant as a variable number.
Typical Exam Questions
- What is the molar mass of water (H2O)? 18.015 g/mol
- How many entities are in one mole of a substance? Approximately 6.02 x 10^23
- Calculate the molar mass of glucose (C6H12O6). 180 g/mol
What Examiners Usually Test
- Understanding of the mole concept and Avogadro's constant.
- Ability to calculate molar mass from atomic masses.
- Application of molar mass in converting between moles and grams.