Citric acid monohydrate is an organic acid. Its molar enthalpy of solution in water has been reported to be ΔsolHm (298.15K, m = 0.0203molkg-1) = (29061±123)Jmol-1. It can be produced by crystallization from mother liquor of citric acid solution at 20-25°C during citric acid synthesis. An investigation of its crystal growth kinetics indicates that growth is linearly dependent on size.