General thermodynamic analysis of the contributions of temperature-dependent chemical equilibria to heat capacities of ideal gases and ideal associated solutions

1984 ◽  
Vol 88 (6) ◽  
pp. 1257-1261 ◽  
Author(s):  
Gilbert J. Mains ◽  
John W. Larson ◽  
Loren G. Hepler
Keyword(s):  
Thermodynamic Analysis ◽  
Heat Capacities ◽  
Temperature Dependent ◽  
Chemical Equilibria ◽  
Ideal Gases ◽  
Associated Solutions

Uniqueness of chemical equilibria in ideal mixtures of ideal gases

2008 ◽  
Vol 76 (9) ◽  
pp. 848-855 ◽  
Author(s):  
Joseph M. Powers ◽  
Samuel Paolucci
Keyword(s):  
Chemical Equilibria ◽  
Ideal Gases

Thermodynamics of aqueous EDTA systems: Apparent and partial molar heat capacities and volumes of aqueous EDTA4−, HEDTA3−, H2EDTA2−, NaEDTA3−, and KEDTA3− at 25 °C. Relaxation effects in mixed aqueous electrolyte solutions and calculations of temperature dependent equilibrium constants

1988 ◽  
Vol 66 (4) ◽  
pp. 881-896 ◽  
Author(s):  
Jamey K. Hovey ◽  
Loren G. Hepler ◽  
Peter R. Tremaine
Keyword(s):  
Equilibrium Constants ◽  
Interaction Model ◽  
Electrolyte Solutions ◽  
Heat Capacities ◽  
Mixed Electrolytes ◽  
Temperature Dependent ◽  
Apparent Molar Heat Capacities ◽  
Partial Molar Heat Capacities ◽  
Relaxation Effects ◽  
Young's Rule

Calorimetric and densimetric measurements have led to apparent molar heat capacities and volumes for aqueous solutions of the mixed electrolytes [(CH3)4N]4EDTA + (CH3)4NOH, Na4EDTA + NaOH, and K4EDTA + KOH, and single electrolytes Na2H2EDTA and [(CH3)4N]3[HEDTA] at 25 °C. We have analyzed these results in terms of Young's rule and Pitzer's ion interaction model to obtain standard state partial molar heat capacities and volumes of EDTA4−(aq), HEDTA3−(aq), H2EDTA2−(aq), NaEDTA3−(aq), and KEDTA3−(aq) at 25 °C. For these calculations it was also necessary to evaluate the "relaxation" contribution to the measured heat capacities of some solutions. The partial molar heat capacities obtained here have been used with enthalpies from previous investigations for calculations of several equilibrium constants over wide ranges of temperature; volumes can be used for similar calculations of the effects of pressure.

Ideal gas processes – and two ideal gas case studies too

2018 ◽  
Author(s):  
Dennis Sherwood ◽  
Paul Dalby
Keyword(s):  
Case Studies ◽  
Constant Pressure ◽  
Ideal Gas ◽  
Heat Capacities ◽  
Carnot Cycle ◽  
State Function ◽  
Ideal Gases ◽  
First Case ◽  
The Ideal

This chapter brings together, and builds on, the results from previous chapters to provide a succinct, and comprehensive, summary of all key relationships relating to ideal gases, including the heat and work associated with isothermal, adiabatic, isochoric and isobaric changes, and the properties of an ideal gas’s heat capacities at constant volume and constant pressure. The chapter also has two ‘case studies’ which use the ideal gas equations in broader, and more real, contexts, so showing how the equations can be used to tackle, successfully, more extensive systems. The first ‘case study’ is the Carnot cycle, and so covers all the fundamentals required for the proof of the existence of entropy as a state function; the second ‘case study’ is the ‘thermodynamic pendulum’ – a system in which a piston in an enclosed cylinder oscillates to and fro like a pendulum under gravity, in both the absence, and presence, of friction.

scholarly journals Venus atmosphere profile from a maximum entropy principle

2007 ◽  
Vol 14 (5) ◽  
pp. 641-647 ◽  
Author(s):  
L. N. Epele ◽  
H. Fanchiotti ◽  
C. A. García Canal ◽  
A. F. Pacheco ◽  
J. Sañudo
Keyword(s):  
Maximum Entropy ◽  
Potential Temperature ◽  
Maximum Entropy Principle ◽  
Temperature Dependent ◽  
Standard Potential ◽  
New Formalism ◽  
Specific Heats ◽  
Ideal Gases ◽  
Entropy Principle ◽  
Atmosphere Of Venus

Abstract. The variational method with constraints recently developed by Verkley and Gerkema to describe maximum-entropy atmospheric profiles is generalized to ideal gases but with temperature-dependent specific heats. In so doing, an extended and non standard potential temperature is introduced that is well suited for tackling the problem under consideration. This new formalism is successfully applied to the atmosphere of Venus. Three well defined regions emerge in this atmosphere up to a height of 100 km from the surface: the lowest one up to about 35 km is adiabatic, a transition layer located at the height of the cloud deck and finally a third region which is practically isothermal.

Optimising an Intercooled Compressor for an Ideal Gas Model

2003 ◽  
Vol 31 (3) ◽  
pp. 189-200 ◽  
Author(s):  
Jeffery D. Lewins
Keyword(s):  
Equation Of State ◽  
Specific Heat ◽  
Ideal Gas ◽  
Heat Capacities ◽  
Perfect Gas ◽  
Temperature Dependent ◽  
Specific Heat Capacities ◽  
Ideal Gas Model

Many of the conventional results obtained when optimising the performance of an intercooler during compression using a perfect gas model can be obtained when the restrictions of the model are relaxed to an ideal gas. That is, we now have temperature-dependent specific heat capacities but retain the equation of state pV = RT. This note illustrates the theme.

Optimal Control of the Heat Release Rate of an Internal Combustion Engine With Pressure Gradient, Maximum Pressure, and Knock Constraints

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Florian Zurbriggen ◽  
Tobias Ott ◽  
Christopher Onder ◽  
Lino Guzzella
Keyword(s):  
Optimal Control ◽  
Pressure Gradient ◽  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Mechanical Work ◽  
Maximum Pressure ◽  
Temperature Dependent ◽  
Ideal Gases ◽  
Burn Rate

In this paper, we present an analysis of the optimal burn rate in an internal combustion engine (ICE) considering pressure gradient, maximum pressure, and knocking. A zero-dimensional model with heat losses is used for that purpose. The working fluids are assumed to behave like ideal gases with temperature dependent gas properties. In the first part, it is assumed that the burn rate can be arbitrarily chosen at every time instance in order to maximize the mechanical work. This leads to an optimal control problem with constraints. In the second part, a Vibe type burn rate is assumed, where the center of combustion, the duration and the form factor can be chosen in order to maximize the mechanical work. This Vibe type burn rate is finally compared with the arbitrary combustion as the benchmark in order to evaluate the potential of the more realistic burn shape.

Thermodynamic Analysis of Reaction Equilibria in Ionic and Molecular Liquid Systems by High-Temperature Raman Spectroscopy

2009 ◽  
Vol 63 (9) ◽  
pp. 1050-1056
Author(s):  
Angelos G. Kalampounias ◽  
Soghomon Boghosian
Keyword(s):  
Raman Spectroscopy ◽  
High Temperature ◽  
Complex Formation ◽  
Equilibrium Constant ◽  
Thermodynamic Analysis ◽  
Raman Band ◽  
Thermal Dissociation ◽  
Temperature Dependent ◽  
Liquid Systems ◽  
Molten Phase

A formalism for correlating relative Raman band intensities with the stoichiometric coefficients, the equilibrium constant, and the thermodynamics of reaction equilibria in solution is derived. The proposed method is used for studying: (1) the thermal dissociation of molten KHSO4 in the temperature range 240–450 °C; (2) the dinuclear complex formation in molten TaCl5–AlCl3 mixtures at temperatures between 125 and 235 °C. The experimental and calculational procedures for exploiting the temperature-dependent Raman band intensities in the molten phase as well as (if applicable) in the vapors thereof are described and used for determining the enthalpy of the equilibria: (1) 2HSO4−( l) ↔ S2O72–( l) + H2O( g), Δ H0 = 64.9 ± 2.9 kJ mol−1; and (2) 1/2Ta2Cl10( l) + 1/2Al2Cl6( l) ↔ TaAlCl8( l), Δ H0 = −12.1 £ 1.5 kJ mol−1.

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