( Chemists ( ( use ( ( a ( pH test ) ) ( that ( measures ( ( ( the concentration ) ( of ( ( hydrogen ions ) ( in ( a ( chemical solution ) ) ) ) ) ) ( to ( determine ( ( ( ( the ( solution 's ) ) ( relative acidity ) ) or ) alkalinity ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Chemists)) (VP (VBP use) (NP (NP (DT a) (NN pH) (NN test)) (SBAR (WHNP (WDT that)) (S (VP (VBZ measures) (S (NP (NP (DT the) (NN concentration)) (PP (IN of) (NP (NP (NN hydrogen) (NNS ions)) (PP (IN in) (NP (DT a) (NN chemical) (NN solution)))))) (VP (TO to) (VP (VB determine) (NP (NP (NP (DT the) (NN solution) (POS 's)) (JJ relative) (NN acidity)) (CC or) (NP (NN alkalinity))))))))))) (. .)))
Chemists use a pH test that measures the concentration of hydrogen ions in a chemical solution to determine the solution's relative acidity or alkalinity.
(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)))) (. .)))