Molar mass

Definition

Molar mass is the mass of one mole of a substance, expressed in grams per mole (g/mol). It is calculated by summing the atomic masses of all atoms in the molecular formula.

5 Must Know Facts For Your Next Test

1. Molar mass allows conversion between grams and moles for a given substance.
2. The molar mass of an element can be found on the periodic table as its atomic weight.
3. For compounds, molar mass is calculated by adding up the molar masses of each constituent element based on its chemical formula.
4. Molar mass is essential for stoichiometric calculations in chemical reactions.
5. It helps determine concentrations in solutions when using molarity.

Review Questions

• How do you calculate the molar mass of a compound?
• Why is molar mass important in stoichiometry?
• What information do you need to find the molar mass of a substance?

Related terms

Mole:

A unit that measures the amount of substance containing exactly $6.022 \times 10^{23}$ entities (atoms, molecules, ions, etc.).

Avogadro's Number:

$6.022 \times 10^{23}$, the number of atoms or molecules in one mole of a substance.

Atomic Mass:

The weighted average mass of an atom of an element, typically expressed in atomic mass units (amu).