Chemistry - 4 Chemical Calculations

Concentration

A measurement of how much solute exists within a certain volume of solvent

What is concentration measured in?

g/dm³ or mol/dm³

1cm³ in dm³ =

0.001dm³

concentration (g/dm³) =

(mass of solute) ÷ (volume of solution)

concentration (mol/dm³) =

(moles of substance) ÷ (volume of solution)

The volume of 1 mole of any gas (at room temperature and pressure) is:

24dm³

24dm³ is known as the:

molar gas volume

number of moles of gas =

(volume of gas (dm³)) ÷ (24dm³)

Relative atomic mass

The weighted mean mass of an atom (including isotopes) of an element compared with 1/12 of the mass of an atom of carbon-12.

Symbol for relative atomic mass:

Aᵣ

Relative formula mass

The sum of the relative atomic masses of the elements as given in the formula for any non-molecular compound.

Symbol for relative formula mass:

Mᵣ

Avogadro's constant

6.02 × 10²³

What is one mole of any substance?

the amount of that substance that contains 6.02 x 10²³ particles

The mass (in g) of one mole of any substance will be the same as...

the substance's relative/formula mass

number of moles =

Mass in g / Mr