quantitative chemistry Flashcards
how do you find relative formula mass
add together the relative atomic masses of all the atoms in that compounds molecular formula
what is avogadro’s constant
6.02 x 10^23
the number of particles in one mole of any substance
what is the equation for mole
the number of moles = mass/Mr
what is conservation of mass
in a chemical reaction mass is always conserved
- no atoms are created or destroy
- only bonds change
what is a chemical change
a rearrangement of the atoms in the reactant, to form the products
what does it mean for a reactant to be a ‘limiting reactant’
it all reacts and limits how much product can be formed
how do you find concentration (in grams per dm^3)
concentration = mass/volume
what is the equation for the volume of gas
volume of gas = moles x 24
what is the atom economy of a reaction
a measure of the proportion of starting materials that end up as useful products
what are the problems with low atom economy
- less sustainable as it will use more resources
- there will be more waste products
what factors should be considered when choosing between two different methods of producing a useful product
- percentage yield
- cost of raw material
- position of equilibrium
- rate of reaction
- cost of maintaining the right condition
- environmental impact of waste products
what are potential reasons as to why the percentage yield maybe be less than 100%
- the reactants may not all react
- there may be side reactions
- some of the products may be lost
