can you all tell me how to find the N-Factor?
is there any rule to find it.
please do tell me.

1.for acids n-facor is defined as the number of H+ ions replaced by 1 mole of acid in a reaction,it is not equal to its basicity.
e.g. n-facor for HCl=1
H2so4=1
2. similarly, n-factor for bases is defined as the no. of OH- ions replaced by 1 mol of base in a reaction,it is not equal to its acidity .
e.g. n-factor for NaOH=1

3. for salts ,
(i)when no atom undergoes change in oxidaion state:n-factor is he total moles of cation/anion charge replaced in 1 mol of salt.
e.g. Na3PO4 + BaCl2 -> NaCl + Ba3(PO4)2
to get one mole of Ba3(PO4)2,2 moles of Na3PO4 are reqi., which means 6moles of Na+ r completely replaced by 3 moles of Ba2+ ions. so, 6 moles of cationic charge is replaced by 2 moles of Na3PO4,thus each mole of Na3PO4 replaces 3 moles of cationic charge.
hence,n-factor of Na3PO4 in this reaction is 3.

(ii)only 1 atom goes in change of O.N.:
let salt A(a)B(b)-
[A(a)+x][B(b)] --> [A(c)+y]D
n-factor for salt=[ ax-ay ] it is never -ve.

(iii) salt: A(a)B(b)
[A(a)+x]B(b) -> [A(c)+y]D + [A(e)+y]F
n-factor =[ax - ay]

(iv) more than 2 atoms undergoes change in O.N.:
[A(a)+x][B(b)] -> [A(c)+y]D + [E(f)][B+z]
n-factor = [ax - ay ] + [-ax - bz]

( )-atoms [subscript]
+()- charge [superscript]

Post edited by: akanksha, at: 2008/03/13 11:32

Post edited by: akanksha, at: 2008/03/13 11:33

Thanks Akansha.