Thermodynamics Research Center / ThermoML | Thermochimica Acta

Thermodynamic investigation of room temperature ionic liquid: The heat capacity and standard enthalpy of formation of EMIES

Zhang, Z.-H.[Zhi-Heng], Tan, Z.-C.[Zhi-Cheng], Sun, L.-X.[Li-Xian], Jia-Zhen, Y.[Yang], Lv, X.-C.[Xue-Chuan], Shi, Q.[Quan]
Thermochim. Acta 2006, 447, 2, 141-146
ABSTRACT
The molar heat capacities of the room temperature ionic liquid 1-ethyl-3-methylimidazolium ethyl sulfate (EMIES) were measured by an adiabatic calorimeter in temperature range from 78 to 390 K. The dependence of the molar heat capacity on temperaturewas given as a function of the reduced temperature X by polynomial equations, Cp,m (JK-1 mol-1) = 178.6 + 50.28X + 2.886X2 -1.362X3 + 0.6616X4 + 7.155X5 [X = (T-132.5)/54.5] for the solid phase (78 187 K) and Cp,m (JK-1 mol-1) = 376.2 + 25.94X-3.397X2 -0.6407X3 + 0.8091X4 + 0.9869X5 [X = (T-292.5)/97.5] for the liquid phase (195 390 K), respectively. According to the polynomial equations and thermodynamic relationship, the values of thermodynamic function of the EMIES relative to 298.15K were calculated in temperature range from 80 to 390K with an interval of 5K. The glass translation of EMIES was observed at 192.85 K. Using oxygen-bomb combustion calorimeter, the molar enthalpy of combustion of EMIES was determined to be cH. m = -5152.6 +- 4.6 kJ mol-1. The standard molar enthalpy of formation of EMIES was evaluated to be fH. m = -579.13 +- 0.51 kJ mol-1 at T = 298.150+-0.001 K.
Compounds
# Formula Name
1 O2S sulfur dioxide
2 CO2 carbon dioxide
3 N2 nitrogen
4 H2O water
5 O2 oxygen
6 C8H16N2O4S 1-ethyl-3-methylimidazolium ethyl sulfate
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 Constraint Phase Method #Points
  • POMD
  • 6
  • Triple point temperature, K ; Glass
  • Glass
  • Liquid
  • Gas
  • Adiabatic calorimetry
  • 1
  • POMD
  • 6
  • Molar heat capacity at constant pressure, J/K/mol ; Liquid
  • Temperature, K; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Vacuum adiabatic calorimetry
  • 170
  • POMD
  • 6
  • Molar heat capacity at constant pressure, J/K/mol ; Glass
  • Temperature, K; Glass
  • Pressure, kPa; Glass
  • Glass
  • Vacuum adiabatic calorimetry
  • 75
  • RXND
  • 1
  • 6
  • 2
  • 3
  • 4
  • 5
  • Molar internal energy of reaction at constant volume, kJ/mol
  • Static bomb calorimetry
  • 1