( Arrhenius ( ( said ( that ( ( a base ) ( is ( ( a compound ) ( that ( ( dissociates ( in water ) ) ( to ( form ( hydroxide ions ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Arrhenius)) (VP (VBD said) (SBAR (IN that) (S (NP (DT a) (NN base)) (VP (VBZ is) (NP (NP (DT a) (NN compound)) (SBAR (WHNP (WDT that)) (S (VP (VBZ dissociates) (PP (IN in) (NP (NN water))) (S (VP (TO to) (VP (VB form) (NP (JJ hydroxide) (NNS ions))))))))))))) (. .)))
Arrhenius said that a base is a compound that dissociates in water to form hydroxide ions.
(ROOT (S (NP (DT A) (PRN (-LRB- -LRB-) (NP (NN n)) (-RRB- -RRB-)) (NN base)) (VP (VBZ is) (NP (NP (DT an) (JJ ionic) (NN compound)) (SBAR (WHNP (WDT that)) (S (VP (VBZ produces) (NP (JJ negative) (NN hydroxide) (NNS ions)) (SBAR (WHADVP (WRB when)) (S (VP (VBN dissolved) (PP (IN in) (NP (NN water)))))))))))))