hiz...
hai~ supposed to be studyin chem now..budden no mood. arghz. can't believe one day passed so quickly. 34 more mins den its tues already
i'm just...v.v.v.v.v.v.v.v.v.v.v.v.v.v.v.v.v.v.v.v.v.v.v.v.v.v. bored.
okiez..shall study chem online

Relative Atomic Mass= average mass of one atom of element/the mass of 1/12 of an atom of carbon-12
Relative Molecular Mass= average mass of one molecule of a substance/1/12*the mass of one atom of carbon-12
% composition of an element in a cpd= no. of atoms of the element in the formula*Ar of the element/Mr of the cpd *100%
Mass of an element in a sample of a cpd= no. of atoms of element in the formula*Ar of the element / Mr of the cpd *mass of sample
Mass of water in a sample of cpd= no. of h2o in the formula*Mr of h2o / Mr of the cpd * mass of the sample

molar mass- the mass of one mole of any substance
no . of moles of atoms in a sample of an element= mass of the same(g)/ molar mass of element(g/mol)
calculating emperical formula:
1. mass of elements
2. molar mass of elements
3. no. of moles
4. simplest ratio
relative molecular mass= n*relative mass of emperical formula
tf, n= relative molecula mass/ relative mass of emperical formula
avocadro's law states that equal volumes of gases contain the same no . of molecules, under the same conditions of temp and pressure
molar volume=24dm3
Volume of gas= no. of moles* molar volume
1dm3=1000cm3
conc.(mol/dm3)= no. of moles/vol. of soln(dm3)
no. of moles=MV
conc.(g/dm3)= no. of grams of solute/vol in dm3
conc.(mol/dm3)- conc.(g/dm3)/molar mass