( Catalysts ( ( ( The kinetics ) ( of ( the ( above reaction ) ) ) ) ( ( ( ( are ( impractically ( slow ( at ( room temperature ) ) ) ) ) , ) ( often ( ( requiring ( several days ) ) ( to ( reach completion ) ) ) ) ) . ) ) )
(ROOT (S (ADVP (RB Catalysts)) (NP (NP (DT The) (NNS kinetics)) (PP (IN of) (NP (DT the) (JJ above) (NN reaction)))) (VP (VBP are) (ADJP (RB impractically) (JJ slow) (PP (IN at) (NP (NN room) (NN temperature)))) (, ,) (S (ADVP (RB often)) (VP (VBG requiring) (NP (JJ several) (NNS days)) (S (VP (TO to) (VP (VB reach) (NP (NN completion)))))))) (. .)))
Catalysts The kinetics of the above reaction are impractically slow at room temperature, often requiring several days to reach completion.
(ROOT (S (SBAR (IN If) (S (NP (DT a) (NN catalyst)) (VP (VBZ runs) (PRT (RP out))))) (, ,) (NP (DT the) (NN reaction)) (VP (VBZ slows)) (. .)))