Overall reaction of metabolism of glucose in the body:
C6H12O6(s)+6O2→6CO2(g)+6H2O(l)
Extra energy used to convert H2O(l) into H2O(g), energy left
=21800=900kJ
Moles of water vaporised from enthalpy of evaporation:
⇒900=nH2O×45
nH2O=45900=20 mole
WH2O=20×18=360g