amount of substance

• the relative atomic mass is the average mass of one atom of an element relative to 1/12 the mass of a carbon 12 atom
• relative molecular mass is the average mass of a molecule compared to 1/12th the mass of a carbon 12 atom
• the avogadro constant is the number of atoms in 12g of carbon 12 (6.022x10^23)
• a mole is the amount of substance that contains 6.022x10^23 particles
• amount of substance unit is mole (mol)
• amount of substance symbol is n
• mol = mass/mr
• avogadros law - under the same temperature and pressure, one mole of any gas will occupy the same volume
• one mole of a gas occupies 24dm^3 at room temperature and pressure
• molar gas volume is the volume per mole of a gas at a specific temperature and pressure
• mol = vol/24
• ideal gas equation is pV = nRT
• mol = conc x vol
• a standard solution is a solution of known concentration
• concentrated - large amount of solute per dm^3 of solvent
• dilute - low amount of solute per dm^3 of solvent
• a species is any particle that takes part in a reaction
• percentage yield describes the efficiency of which reactants are converted into products in a chemical reaction
• percentage yield = actual yield/theoretical yield x 100
• atom economy tells us how many useful products are made from a given amount of reactants
• atom economy = desired mr/total product mr x 100
• 100% yield does not always mean 100% atom economy
• addition reactions have 100% atom economy