The Mole Concept

What is the stoichiometry of a reaction?

The ratio of reactants and products in a balanced equation is called the

stoichiometry of the reaction.

Define mole.

One mole is the amount of substance which has the same number of

specific particles (atoms, ions or molecules) as there are atoms in exactly

12g of the 12C isotope.

What is molar mass.

The molar mass, M, is the mass of one mole of specified substance in

grams.

What does the empirical formula show?

An empirical formula of a compound shows the simplest whole number

ratio of the elements present in a molecule or formula unit of the

compound.

What does the molecular formula show?

A molecular formula shows the total number of each type of atom

present in a molecule.

State Avogadro’s Law.

Avogadro’s law states that equal volumes of all gases at the same

temperature and pressure have equal numbers of molecules.

What are the conditions and volume at s.t.p?

• Temperature: 0 °C (273 K)

• Pressure: 1 atm (101.3 kPa)

Volume- 22.4 dm3

What are the conditions and volume at r.t.p?

• Temperature: 25 °C (298 K)

• Pressure: 1 atm (100 kPa)

Volume - 24.0 dm3