Chemistry unit 3 Flashcards
What is the law of the conservation of mass
mass of products = mass of reactants. energy cannot be created or destroyed in the system, only usefully transferred
What is the relative formula mass of a product and how do we work it out
The Mr of a product is the sum of the relative atomic masses of a compound. we add the relative atomic masses together
How do we work out the relative atomic mass of an element
times the abundancy of each of its isotopes by the mass number in that isotope, then add them all together and divide by 100.
What is a mole
a unit we use to measure the amount of a chemical product measured in mol
What is the formula that links Mol, Mr and mass
Mol = mass/Mr or mass = mol x Mr
What is Avogadro’s constant as a concept and as a number
the number of atoms in a mole. 6.02 x10^23
What is a limiting reactant
in a reaction, there will be one substance that you run out of as in a reaction, you always put excess to get the maximum yield. The limiting reactant restricts how much product is made
How do we work out the limiting reactant
work out the moles of both reactants and see which one is lower
What is the equation which links mass, concentration and volume
mass= conc x vol
What is the equation to work out the percentage yield of a reaction
( amount of product produced/ maximum amount of product possible ) x 100
What is atom economy
How much of the Reactants has become useful product
How do we work out atom economy
( Mr of useful product / Mr of reactants ) x 100
What two ways can we measure concentration
mol/dm^3 or g/dm^3
formula involving concentration, moles and volume
conc = mol/vol
formula involving Moles volume and vol of 1 mol (24dm^3)
Vol = mol x 24
