( ( pH pH ) ( ( is ( ( a measure ) ( of ( ( the ( hydrogen ( ion concentration ) ) ) ( in water ) ) ) ) ) . ) )
(ROOT (S (NP (NN pH) (NN pH)) (VP (VBZ is) (NP (NP (DT a) (NN measure)) (PP (IN of) (NP (NP (DT the) (NN hydrogen) (NN ion) (NN concentration)) (PP (IN in) (NP (NN water))))))) (. .)))
pH pH is a measure of the hydrogen ion concentration in water.
(ROOT (S (NP (NP (DT The) (NN concentration)) (PP (IN of) (NP (NP (DT the) (NN hydrogen) (NN ion)) (PP (IN in) (NP (DT a) (NN solution)))))) (VP (MD can) (VP (VB be) (VP (VBN calculated) (SBAR (WHADVP (WRB when)) (S (NP (DT the) (NN ph)) (VP (VBZ is) (VP (VBN known)))))))) (. .)))
The concentration of the hydrogen ion in a solution can be calculated when the ph is known.