ABSTRACT

The enthalpy of formation of zinc acetate dihydrate (Zn(CH3COO)_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 2H2O.

Compounds

#	Formula	Name
1	HNaO	sodium hydroxide
2	C	graphite
3	Zn	zinc
4	H2	hydrogen
5	O2	oxygen
6	ClH	hydrogen chloride
7	C4H10O6Zn	zinc(II) acetate dihydrate
8	OZn	zinc(II) oxide
9	C2H4O2	acetic acid
10	H2O	water

Datasets

The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type	Compound-#	Property	Variable	Phase	Method	#Points
POMD	9 1 10	Molar enthalpy of solution, kJ/mol ; Liquid	Amount concentration (molarity), mol/dm3 - 9; Liquid Temperature, K; Liquid Pressure, kPa; Liquid Solvent: Amount concentration (molarity), mol/dm3 - 1; Liquid	Liquid	Titration calorimetry	1
POMD	1 7 10	Molar enthalpy of solution, kJ/mol ; Liquid	Amount concentration (molarity), mol/dm3 - 7; Liquid Temperature, K; Liquid Pressure, kPa; Liquid Solvent: Amount concentration (molarity), mol/dm3 - 1; Liquid	Liquid	Titration calorimetry	1
POMD	7 6 10	Molar enthalpy of solution, kJ/mol ; Liquid	Amount concentration (molarity), mol/dm3 - 7; Liquid Temperature, K; Liquid Pressure, kPa; Liquid Solvent: Amount concentration (molarity), mol/dm3 - 6; Liquid	Liquid	Titration calorimetry	1
POMD	9 6 10	Molar enthalpy of solution, kJ/mol ; Liquid	Amount concentration (molarity), mol/dm3 - 9; Liquid Temperature, K; Liquid Pressure, kPa; Liquid Solvent: Amount concentration (molarity), mol/dm3 - 6; Liquid	Liquid	Titration calorimetry	1
POMD	1 8 10	Molar enthalpy of solution, kJ/mol ; Liquid	Amount concentration (molarity), mol/dm3 - 8; Liquid Temperature, K; Liquid Pressure, kPa; Liquid Solvent: Amount concentration (molarity), mol/dm3 - 1; Liquid	Liquid	Titration calorimetry	1
RXND	9 8 7 10	Molar enthalpy of reaction, kJ/mol			Solution calorimetry	1
RXND	9 8 7 10	Molar enthalpy of reaction, kJ/mol			Solution calorimetry	1
RXND	2 3 7 4 5	Molar enthalpy of reaction, kJ/mol			Solution calorimetry	1
RXND	2 3 7 4 5	Molar enthalpy of reaction, kJ/mol			Solution calorimetry	1

Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Enthalpy of formation of zinc acetate dihydrate

Hughes, J. T.[James T.], Navrotsky, A.[Alexandra]

ABSTRACT