( ( PH pH ) ( ( is ( ( a measure ) ( of ( how ( ( ( ( acidic or ) alkaline ) ( a solution ) ) is ) ) ) ) ) . ) )
(ROOT (S (NP (NNP PH) (NNP pH)) (VP (VBZ is) (NP (NP (DT a) (NN measure)) (PP (IN of) (SBAR (WHADVP (WRB how)) (S (NP (ADJP (JJ acidic) (CC or) (JJ alkaline)) (DT a) (NN solution)) (VP (VBZ is))))))) (. .)))
PH pH is a measure of how acidic or alkaline a solution is.
(ROOT (S (NP (NP (DT The) (NN acidity)) (PP (IN of) (NP (DT a) (NN solution)))) (VP (VBZ is) (ADVP (RB typically)) (VP (VBN assessed) (ADVP (RB experimentally)) (PP (IN by) (NP (NP (NN measurement)) (PP (IN of) (NP (PRP$ its) (NN ph.)))))))))