( Chemical ( ( ( equations obey ) ( ( ( the law ) ( of ( conservation ( of mass ) ) ) ) ( which ( states ( that ( matter ( ( can not ) ( be ( ( ( created or ) destroyed ) ( during ( normal ( chemical changes ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Chemical)) (VP (VBZ equations) (ADVP (RB obey)) (NP (NP (DT the) (NN law)) (PP (IN of) (NP (NP (NN conservation)) (PP (IN of) (NP (NN mass))))) (SBAR (WHNP (WDT which)) (S (VP (VBZ states) (SBAR (IN that) (S (NP (NN matter)) (VP (MD can) (RB not) (VP (VB be) (VP (VBN created) (CC or) (VBN destroyed) (PP (IN during) (NP (JJ normal) (NN chemical) (NNS changes))))))))))))) (. .)))
Chemical equations obey the law of conservation of mass which states that matter cannot be created or destroyed during normal chemical changes.
(ROOT (S (NP (NNP Matter)) (VP (MD can) (RB not) (VP (VB be) (VP (VBN created) (CC or) (VBN destroyed) (PP (IN in) (NP (DT a) (NN chemical) (NN reaction)))))) (. .)))