Quantitative chem

• Conservation of mass

  Total mass before reaction = total mass after reaction
• Decrease in mass in a reaction

  Normally because a gas is produced in the reaction and lost to the surroundings
• Increase in mass in a reaction

  Normally because one of the reactants is a gas
• Relative formula mass (Mr): The sum of the relative atomic masses of each atom in a substance
• State symbols

  s- solid

  l- liquid

  g- gas

  aq- aqueous or dissolved in water
• One mole of a substance: 6.02^23 atoms, ions, or molecules
• Avogadro's constant: The number of particles in one mole of a substance
• Formula connecting Moles, Mr, and Mass

  Moles = Mass/Mr
• Limiting reactant: The reactant that is completely used up in a chemical reaction
• Concentration

  The amount of solute in a volume of solvent

  Unit of concentration: g/dm^3
• Formula connecting Concentration, Mass, and Volume

  Concentration = Mass/Volume