The enthalpy of formation of zinc acetate dihydrate (Zn(CH 3COO)2 · 2H2O) was measured with respect to crystalline zinc oxide (ZnO), glacial acetic acid (CH3COOH) and liquid water by room temperature solution calorimetry. The enthalpy of formation was verified by utilizing two independent thermodynamic cycles, using enthalpy of solution measurements in 5 mol · L-1 sodium hydroxide (NaOH) and in 5 mol · L-1 hydrochloric acid (HCl) solutions. The enthalpy of the reaction ZnO (cr) + 2CH3COOH (l) + H2O (l) to form Zn(CH3COO)2 · 2H2O (cr) is -(65.78 ± 0.36) kJ · mol-1 for measurements in 5 mol · L-1 NaOH and -(66.25 ± 0.17) kJ · mol -1 for measurements in 5 mol · L-1 HCl. The standard enthalpy of formation of Zn(CH3COO)2 · 2H2O from the elements is -(1669.35 ± 1.30) kJ · mol-1. This work provides the first calorimetric measurement of the enthalpy of formation of Zn(CH3COO)2 · 2H 2O.
- Enthalpy of formation
- Solution calorimetry
- Zinc acetate
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Materials Science(all)
- Physical and Theoretical Chemistry