In between`CH_(3)COOHandCH_(3)COO^(Theta)`, which one is more resonance stabilised and why?

Explanation

Both `CH_(3)COOH` and `CH_(3)COO^(-)` are resonance hybrids of two canonical forms. But one of the resonance structures of `CH_(3)COOH` involes separation of charge, while none of the resonance structures of `CH_(3)COOH^(-)` involes any separation of charge (also these structures are equivalent). Hence `CH_(3)COO^(-)` is more resonance stabilised compared to `CH_(3)COOH`.