Question

explain why H20 is neutral whereas H2s is acidic

Answer 1

due to different chemical combination

Answer 2

S is much larger atom than O, so the H–S bond is much longer and weaker than H–O; hence H2O is weaker acid than H2S. HF is stronger than H2S because the small F- ion bonds more strongly to the water molecules than does the larger HS- 

HOPE IT HELPS............