( ( ( ( ( A calorimeter ) ( is ( ( a ( ( thermally insulated ) container ) ) ( where ( ( a ( reaction system ) ) ( can ( be performed ) ) ) ) ) ) ) and ) ( ( ( the ( energy exchange ) ) ( between ( ( ( the system ) and ) ( its surroundings ) ) ) ) ( can ( be measured ) ) ) ) . )
(ROOT (S (S (NP (DT A) (NN calorimeter)) (VP (VBZ is) (NP (NP (DT a) (ADJP (RB thermally) (JJ insulated)) (NN container)) (SBAR (WHADVP (WRB where)) (S (NP (DT a) (NN reaction) (NN system)) (VP (MD can) (VP (VB be) (VP (VBN performed))))))))) (CC and) (S (NP (NP (DT the) (NN energy) (NN exchange)) (PP (IN between) (NP (NP (DT the) (NN system)) (CC and) (NP (PRP$ its) (NNS surroundings))))) (VP (MD can) (VP (VB be) (VP (VBN measured))))) (. .)))
A calorimeter is a thermally insulated container where a reaction system can be performed and the energy exchange between the system and its surroundings can be measured.
(ROOT (S (NP (DT A) (JJ sealed) (, ,) (JJ vacuum-insulated) (NN reaction) (NN flask)) (VP (VBZ approximates) (NP (NP (DT the) (NN condition)) (PP (IN of) (NP (NP (DT a) (VBN isolated) (NN system)) (, ,) (SBAR (WHPP (IN in) (WHNP (WDT which))) (S (NP (CC neither) (NP (NN matter)) (CC nor) (NP (NN heat))) (VP (MD can) (VP (VB be) (VP (VBN exchanged) (PP (IN between) (NP (NN system) (CC and) (NNS surroundings)))))))))))) (. .)))
A sealed, vacuum-insulated reaction flask approximates the condition of a isolated system, in which neither matter nor heat can be exchanged between system and surroundings.