( ( ( A measure ) ( of ( ( ( acidity and ) alkalinity ) ( of ( ( ( a solution ) , ) ( taken ( by ( measuring ( ( the ( relative concentration ) ) ( of hydrogen ) ) ) ) ) ) ) ) ) ) ( ( ions ( in ( the solution ) ) ) . ) )
(ROOT (S (NP (NP (DT A) (NN measure)) (PP (IN of) (NP (NP (NN acidity) (CC and) (NN alkalinity)) (PP (IN of) (NP (NP (DT a) (NN solution)) (, ,) (VP (VBN taken) (PP (IN by) (S (VP (VBG measuring) (NP (NP (DT the) (JJ relative) (NN concentration)) (PP (IN of) (NP (NN hydrogen))))))))))))) (VP (VBZ ions) (PP (IN in) (NP (DT the) (NN solution)))) (. .)))
A measure of acidity and alkalinity of a solution, taken by measuring the relative concentration of hydrogen ions in the solution.
(ROOT (S (NP (NP (DT The) (NN concentration)) (PP (IN of) (NP (NP (NN hydrogen) (NNS ions)) (PP (IN in) (NP (DT a) (NN solution)))))) (VP (VBZ is) (VP (VBN called) (ADVP (RB acidity)))) (. .)))