some basic concepts of chemistry
law of conservation of mass
During any physical or chemical change total mass of the product obtained is always = total mass of reactants
It was given by A.Lavoisier (father of chemistry )
A + B ----- AB ( sum of mass of reactants = sum of mass of prouducts )
Ex ; C + O2 ---- CO2 C - 1 : 2 CO2 1 : 2
Law of constant composition
It was given by proust
Avagadro's hypothesis
Mole concept
A chemical compound no matter from which source it is obtained always contain same elements in definite proportion by mass
Ex : H2 + CL2 ------ 2HCL
under identical conditions of temp and pressure = vol of all gases contain = no. of molecules
formulas
no. of moles = mass given / mol mass
wt by wt percentage = mass of solute / mass of sol x 100
w by vol percent = mass of solute x vol of sol
mole fraction
= no. of mol of given component / total no.of sol
Mole fraction
if a particular component in a sol is ratio of number of moles of that component its total no. of mol of all component in sol
m.f = no. of mol of given component / total no. of mol in sol
no.of mol = mass / molecular mass
gram equivalent
eq. mass = mol wt / X
acids - X basicity H+ ions
base - X acidity OH- ions
grm equivalent = molecular mass / eq wt