What is n- factor.??

n-factor is defined as the number of H+ions replaced by 1 mole of acid in a reaction.n-factor for acid is not equal to its basicity i.e. the number of moles of replaceable H+ atoms present in one mole of acid.For ex--n-factor of H2SO4= 1 or 2, depending upon extent of reaction it undergoes.
1).H2SO4+ NaOH → NaHSO4+ H2O
Although one mole of H2SO4ahs 2 replaceable H atoms but in this reaction H2SO4has given only one H+ion, so its n-factor would be 1.
2). H2SO4+ 2NaOH → Na2SO4+ 2H2O
The n-factor of H2SO4in this reaction would be 2.
Similarly,
for bases,n-factor is defined as the number of OH–ions replaced by 1 mole of base in a reaction.n-factor is not equal to its acidity i.e. the number of moles of replaceable OH–ions present in 1 mole of base.
For example--n-factor of NaOH = 1
n-factor of Zn(OH)2= 1 or 2
n factor of Ca(OH)2= 1 or 2