stoichiometry Flashcards
what is a empirical formula of a compound
the simplest whole number ratio of the different atoms or ions in a compound
ionic compound formula
cross over method
why are atoms electricly neutral
because the number of protons and electrons are the same.
what is the valecy of a atom
the number of electrons gained, lost or shared- this determains the ability of the atom to combine with other elements- determains the number of outer shells.
what are spectator ions
ions which dont change during a equation
what is relative atomic mass
as the average mass of the isotopes of an element compared to 1/12th of the mass of an atom of
12C
what is relative molecular mass
Mr, as the sum of the relative atomic masses. Relative formula mass, Mr, will be used for ionic
compounds
what is a mole (n)
the unit of amount of substance, one mole contains 6.02 × 1023 particles, e.g. atoms, ions,
molecules; this number is the Avogadro constant.
what is the formula of moles
n=m/mr
percentage yield
amount of usable product
actual yield/ theoretical yield x 100
what is a molecular formula
the number and type of different atoms in one molecule
translation of dm
- cm etc
dm- cm = *1000
cm-dm = /1000
formula for number of moles in terms of gas
volume of gas/ 24
percentage purity formula
(mass of pure product/mass of impure product)×100
number of moles in terms of concentration
concentration (mol/dm3) * volume (dm3)
