The mole and the Avogadro constant (3.1.2.2)

What is Avogadro’s constant?

Avogadro’s constant - the number of particles in a mole - 6.022 × 10²³

What are the two ways that moles can be calculated?

n = m/Mr

n = c x v

n = v/24 (at room temperature + pressure)

Where n is moles (mol)

Where m is mass (g)

Where Mr is relative molecular mass (technically no unit but good to imagine it as gmol^-1)

Where c is concentration (moldm^-3)

Where v is volume (dm^-3)

How can the number of particles be calculated?

No. of particles = moles of substance x Avogadro’s constant

How can the mass of an atom or molecule be calculated?

m = A(M)r/N_a

Where m is mass (g)

Where A(Mr) is atomic/molecular mass

Where N_a is Avogadro’s constant