Chemistry ✿ Quantitative chemistry

conservation of mass

no atoms are lost or made during a reaction

• the mass of the products equals the mass of the reactants

in some cases, why might mass change in a reaction?

when a solid reacts with a gas,

• gas may be released into the atmosphere

• gases mass wouldn’t have been taken in account before the reaction

moles (mol)

measure of chemical amounts

Avogadro constant

6.02 x 10²³

limiting reactant

reactant that is isn’t fully used up in a reaction

why are reactants sometimes used in excess?

to ensure the other reactants are used up

g/dm³

measure of concentration of a solution

equation for concentration

mass (g) / volume (dm³)

equation for moles

mass (grams) / rams

Relative formula mass (Mr)

a measurement of all the relative atomic masses of the atoms in a compound

The mass of 1 mole of a substance is equal to it’s ________ _________ _____ or ________ _____ in grams

relative formula mass or atomic mass

cm³ into dm³

divide by 1000