Atoms, Moles and Stoichiometry

What is relative atomic mass?

The weighted mean mass of an atom of an element relative to an atom of carbon-12 having a mass of exactly 12 units

What is molecular mass?

The weighted average of the mass of a molecule relative to an atom of carbon-12 having a mass of exactly 12 units

What is relative isotopic mass?

The mass of an atom of an isotope on scale relative to an atom of carbon-12 having a mass of exactly 12 units

What is relative formula mass?

The weighted average masses of the formula units relative to an atom of carbon-12 having a mass of exactly 12 units

What does 'amount of substance mean'?

* Measured in mass
* Based upon Avogadro’s constant
* Measure the number of atoms in a substance

What is the Avogadro Constant? (NA)

The number of atoms per mole of substance
NA = 6.02×10²³ mol⁻¹

Define the mole

The amount of any substance containing as many particles as there are in exactly 12g of carbon-12

What is meant by the term empircal formula?

The simplest whole number ratio of atoms of each element present in a compound

What is molecular formula?

The actual number of of atoms of each element present in a compound

What is concentration?

The amount of solute (usually in moles) dissolved per dm3 of solution
C= n/v

What is stoichiometry?

The proportions of reactants and products