4. The Mole & Stoichiometry I

a mole lot of fun!

mole

a unit of counting, one mole of a substance is the amount of that substance that contains 6x10^23 particles of that substance

moles -> grams

multiply by RAM/RMM

grams -> moles

divide by the RAM/RMM

moles -> litres (STP)

multiply by 22.4

moles -> litres (RTP)

multiply by 24

litres (STP) -> moles

divide by 22.4

litres (RTP) -> moles

divide by 24

moles -> cm^3 (STP)

multiply by 22400

moles -> cm^3 (RTP)

multiply by 24000

cm^3 (STP) -> moles

divide by 22400

cm^3 (RTP) -> moles

divide by 24000

moles -> particles

multiply by 6x10^23

particles -> moles

divide by 6x10^23

to calculate % composition by mass

total mass of element in compound/total mass of compound x 100

reactants

substances that react together in a chemical reaction

products

substances that are formed in a chemical reaction

law of conservation of mass

the total mass of the products of a chemical reaction is the same as the total mass of the reactants

law of conservation of matter

in any chemical reaction, matter is neither created nor destroyed but merely changes from one form into another

golden rule for manipulating equations

you can only change big numbers, you cannot change little numbers

when balancing equations…

follow CHO - carbons, hydrogens, oxygens

to balance equations

count atoms on LHS and RHS, balance elements (follow CHO), check LHS and RHS

to use given ratios in balanced equations

convert given info into moles, find relationship between balanced and real, apply to all mole in balanced