( ( To ( determine ( ( the ( activation energy ) ) ( of ( a ( chemical reaction ) ) ) ) ) ) . )
(ROOT (S (VP (TO To) (VP (VB determine) (NP (NP (DT the) (NN activation) (NN energy)) (PP (IN of) (NP (DT a) (NN chemical) (NN reaction)))))) (. .)))
To determine the activation energy of a chemical reaction.
(ROOT (S (NP (NP (DT The) (NN amount)) (PP (IN of) (NP (NP (NN energy)) (VP (VBN required) (S (VP (TO to) (VP (VB begin) (NP (DT a) (JJ chemical) (NN reaction))))))))) (VP (VBZ is) (VP (VBN known) (PP (IN as) (NP (DT the) (NN activation) (NN energy))))) (. .)))