question_answer

\[{{H}_{2}}S\]is a stronger acid than \[{{H}_{2}}O,\] Explain.

Answer:

                Hydrogen sulphide\[({{H}_{2}}S)\] is a stronger acid \[({{K}_{a}}=1.0\times {{10}^{-7}})\] than water \[({{K}_{a}}=1.0\times {{10}^{-14}})\] because S-H bond is longer than O-H bond. Its bond dissociation enthalpy is therefore, less as compared to that of O-H bond in \[{{H}_{2}}O\].