Amount of Substance
Measured in moles and given the symbol n.
Avogadro's Constant (NA)
The number of particles per mole; equal to 6.02 x 10^23
Moles and Particles
Moles = no. of particles/6.02 x 10^23
No. of particles = moles x 6.02 x 10^23
Moles and Mass
Mass(g) = moles x molar mass
Moles = mass/molar mass
Molar mass = mass/moles
Molar Mass (Mr)
The mass of 1 mole of a substance.
The lowest whole number ratio of atoms of each element in a compound.
The actual ratio of number of atoms of each element in a compound.
Moles in Solution
Moles = concentration (moldm-3) x volume (dm3)
Concentration = moles/volume
Volume = moles/concentration
Moles in Gas
Volume(dm^3) = moles x 24
Moles = volume/24
A soluble base which releases OH- ions in solution.
Formed when the H+ ion of an acid is replaced by a metal ion or ammonium ion (NH4^+)
The compound which remains when the water of crystallisation is removed from a hydrated salt.
A complex compound which has water molecules incorporated.
Water of Crystallisation
Water molecules which make up part of the crystal structure of a compound and are easily removed by heating.