quantitative chemistry Flashcards
in a reaction what is the only thing that changes
the bonds between the atoms
what is the mass number
number of protons and neutrons
what is the ar
the relative atomic mass(average mass of the isotopes - bottom number-biggest
what is the mr
the relative formula mass(mass of all atoms in a compound)
% mass of an element
the ar x the number of atoms of that element /mr of compound x100
why is mass changed if reactants or products are gases
as the mass of gases is not accounted for
what are random errors
Inaccurate reading of results from an instrument that can be affected by changes in environmnent(air currents in a room/changes in temperature in a lab)
what is systematic error
error that stem from faulty or poorly designed experimental procedure(reading the burette below eye level)
1 mole of a substance contains
6.02 x 10 to the power of 23 particles
what is the mass of one mole of a substance =
the relative formula mass(mr)
moles =
mass/mr
