Question

how to identify active hydrogen in organic compound

Answer 1

Being 'acidic' means, it has tendency to be released as H+ ion (or H atom without its only electron). So, if any H-atom is attached to another atom or group of atoms with higher electronegativity, that H-atom is a potential acidic H-atom……

Generally hydrogen attached to S,N,O,F and Carbon ‘Sp’ is considered as active hydrogen……….(you can directly see)

Examples include:

H2SO4, HF, NH3, NaOH, etc……