C2 Flashcards
RAM
the weighted average mass of an atom of an element, taking into account its naturally occurring isotopes, relative to 1/12 the RAM of an atom of C-12.
Mr
the mass of a molecule compared to 1/12 the RAM of an atom of C-12.
Avogadro’s constant
the number of atoms in 12g of C-12.
empirical formula
the formula that represents the simplest whole number ratio of the atoms of each element present in a compound.
molecular formula
the actual number of atoms of each element present in a compound
% yield
actual/ theoretical x 100
% atom economy
mass of desired product/ mass of reactants x 100
ideal gas equation
PV= nRT
P= pressure in Pa
V= volume in m^3
n= no. moles
R= gas constant = 8.31 JK-1mol-1
T= temp in K
the kinetic model of an ‘ideal gas’
- particles move around freely
- most atoms are empty space
- when they collide with each other and the walls of their container, they exert a tiny force
importance of % yield
to get as much product as possible from the reaction.
importance of % atom economy
maximise the mass of reactants that end up as desired products
% uncertainty
(no. of readings x uncertainty )/ measured value x 100
