C3 Flashcards
what’s the law of conservation?
no atoms are lost or made during a chemical reaction
when chemicals react atoms are not lost they are just?
rearranged
the mass of the products is equal to
the mass of the reactants
what is atom economy
a measure of the amount of starting materials that end up as useful products
high atom economy is best
what’s the formula for calculating atom economy
Relative formula mass of desired product / sum of relative formula masses of all reactants
x 100
Mr and Ar are different things, what are they
Mr is relative formula mass
Ar is relative atomic mass
how do you work out relative formula mass of a compound
add up the total relative atomic mass of all atoms within a compound
how do you work out the percentage mass of an element in a compound
Ar x number of atoms of that element / Mr of the compound
x 100
when the mass of the products is higher than the reactants, this is because
a gas is involved
what is concentration
the amount of a substance in a certain volume
what is a decimetre
how do you convert cm to dm
1/10 of a metre/10 cm
divide by 1000
what is concentration measured in
g/dm3
what’s the equation for concentration
mass of dissolved substance /
volume of solvent
