use of amount of substance in relation to masses of pure substances

CONCERNTRAION

can be measured in mass per unit volume

describe the mass of a substance in a certain volume of solution

concerntration (g/dm3) = mass (g) / volume (dm3)

LIMITING FACTORS

any other reactants are in excess

determine the amount of products

reactants which get used up, causing the reaction to stop

amount of product formed is directly proportional to amount of limiting the reactant

calculate the mass product formed using the mass of the limiting reactant and the balanced equation

  1. calculate moles of limiting reactant
  2. determine ratio of limiting reactant to product
  3. final mass of product

MOLES

moles= mass (g)/Mr

the atoms of molecules or ions in a mole of a given substance is the Avogardo constant

Avogardo constant: 6.02 x 10^23

EQUATIONS

equal number of atoms each element on each side of the equation

calculate the masses of reactants and products from balanced equations

  1. calculate moles of known reactants/products 2.determine ratio of known reactants/products to known reactants/products
  2. find mass of unknown reactants/products