( pH ( ( is ( ( a scale ) ( that ( measures ( how ( ( ( ( acidic or ) basic ) ( a solution ) ) is ) ) ) ) ) ) . ) )
(ROOT (S (NP (NN pH)) (VP (VBZ is) (NP (NP (DT a) (NN scale)) (SBAR (WHNP (WDT that)) (S (VP (VBZ measures) (SBAR (WHADVP (WRB how)) (S (NP (ADJP (JJ acidic) (CC or) (JJ basic)) (DT a) (NN solution)) (VP (VBZ is))))))))) (. .)))
pH is a scale that measures how acidic or basic a solution is.
(ROOT (S (PP (IN As) (NP (NN ph) (NNS increases))) (, ,) (NP (DT a) (NN solution)) (VP (VBZ becomes) (ADJP (RBR more) (JJ basic))) (. .)))