Mole

Definition

A mole is a unit that measures the amount of substance, defined as containing exactly 6.02214076 x 10^{23} particles (atoms, molecules, ions, or electrons). It provides a bridge between the atomic world and the macroscopic world.

5 Must Know Facts For Your Next Test

1. One mole of any substance contains Avogadro's number ($6.02214076 \times 10^{23}$) of particles.
2. The molar mass of a substance is the mass of one mole of that substance, usually expressed in grams per mole (g/mol).
3. To find the number of moles, divide the given mass by the molar mass: $n = \frac{mass}{molar\ mass}$.
4. Moles can be used to convert between atomic/molecular scale measurements and macroscopic quantities.
5. In chemical reactions, coefficients in balanced equations represent the ratio of moles of each substance.

Review Questions

• What is Avogadro's number and why is it significant?
• How would you calculate the number of moles in a sample if you know its mass and molar mass?
• Why are moles important for understanding chemical reactions?

Related terms

Avogadro's Number:

The number $6.02214076 \times 10^{23}$, representing the number of atoms or molecules in one mole of a substance.

Molar Mass:

The mass in grams of one mole of a given substance.

Stoichiometry:

The calculation of reactants and products in chemical reactions using relationships based on balanced equations.