Select�@reaction�@System

H + X2 �¨ HX + X (X=F,Cl)

CO2 + nH2O �¨ H2CO3 + H2O (n=1,2)

SO3 + H2O �¨ H2SO4

N2O4 + H2O �¨ HNO3 + HNO2

Diels-Alder reaction

C6H4(CO)2O + H2O �¨ C6H4(COOH)2

CH3COOH + C6H5NH2 �¨ C6H5NHCOCH3 + H2O