C3-Quantitative Chemistry

what is relative formula mass

the sum of the relative atomic masses of the atoms in a molecule

percentage mads of an element in a compound

(Ar x number of atoms) / Mr of the compound

Ar

relative atomic mass

Mr

relative formula mass

Mole

the unit for the amount of a substance

(way to count no. of particles)

Mass formula

MrMole

(Mr x moles)

conservation of mass

during a chemical reaction, atoms aren't destroyed or created so no mass is lost or gained

what can cause a change in mass in a chemical reaction?

unsealed reactiom vessel allows interference from gases

increase: reactant found gas in the air to react with and forms some of the product

decrease: one product is a gas and escaped the container

big number in molecular formula

how many moles

small number in molecular formula

how many atoms of the element

when do reactions stop

When one reactant is used up (limiting reactant)

What is the amount of product directly proportional to?

The amount of limiting reactant

concentration

the anount of a substance in a volume of a solution

concentration formula

mass or moles / volume