( ( ( The volume ) ( of gas ) ) ( ( increases ( because ( ( ( the number ) ( of moles ) ) ( is increased ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN volume)) (PP (IN of) (NP (NN gas)))) (VP (VBZ increases) (SBAR (IN because) (S (NP (NP (DT the) (NN number)) (PP (IN of) (NP (NNS moles)))) (VP (VBZ is) (VP (VBN increased)))))) (. .)))
The volume of gas increases because the number of moles is increased.
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (PRP you)) (VP (VBP add) (NP (NP (NNS moles)) (PP (IN of) (NP (NP (NN gas)) (PP (TO to) (NP (DT a) (NN baloon)))))) (PP (IN by) (S (VP (VBG blowing) (NP (PRP it)) (PRT (RP up)))))))) (, ,) (NP (DT the) (NN volume)) (VP (VBZ increases)) (. .)))