<s>[INST] Chemical Reactions . Dehydration, such as that occurring in steam distillation, decomposes water molecules into hydrogen and oxygen in the overall chemical reaction:
H2O ( l ) + Heat → H2 ( g ) + 1/2 O2 ( g )
(a) Is this reaction endothermic or exothermic?
(b) What is the temperature change as water decomposes and what sign does the heat of reaction ( qrxn ) have?[/INST]