( pH ( ( measures ( ( the ( ( acidity or ) alkalinity ) ) ( of solutions ) ) ) . ) )
(ROOT (S (NP (NN pH)) (VP (VBZ measures) (NP (NP (DT the) (NN acidity) (CC or) (NN alkalinity)) (PP (IN of) (NP (NNS solutions))))) (. .)))
pH measures the acidity or alkalinity of solutions.
(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.)))))))))