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- https://chem.libretexts.org/Courses/Lansing_Community_College/LCC%3A_Chem_151_-_General_Chemistry_I/Text/06%3A_Thermochemistry/6.03%3A_EnthalpyAt constant pressure, heat flow (q) and internal energy (U) are related to the system’s enthalpy (H).
- https://chem.libretexts.org/Courses/Los_Angeles_Trade_Technical_College/LATTC_Hybrid_Chem_51/07%3A_Energy_and_Chemistry/7.3%3A_Enthalpy_and_Chemical_ReactionsEvery chemical reaction occurs with a concurrent change in energy. The change in enthalpy equals heat at constant pressure. Enthalpy changes can be expressed by using thermochemical equations. Enthalp...Every chemical reaction occurs with a concurrent change in energy. The change in enthalpy equals heat at constant pressure. Enthalpy changes can be expressed by using thermochemical equations. Enthalpy changes are measured by using calorimetry.
- https://chem.libretexts.org/Courses/Nassau_Community_College/General_Chemistry_1/09%3A_Thermochemistry/9.04%3A_EnthalpyIf a chemical change is carried out at constant pressure and the only work done is caused by expansion or contraction, q for the change is called the enthalpy change with the symbol ΔH. Examples of en...If a chemical change is carried out at constant pressure and the only work done is caused by expansion or contraction, q for the change is called the enthalpy change with the symbol ΔH. Examples of enthalpy changes include enthalpy of combustion, enthalpy of fusion, enthalpy of vaporization, and standard enthalpy of formation. If the enthalpies of formation are available for the reactants and products of a reaction, the enthalpy change can be calculated using Hess’s law.
- https://chem.libretexts.org/Bookshelves/Introductory_Chemistry/Beginning_Chemistry_(Ball)/07%3A_Energy_and_Chemistry/7.06%3A_Hess's_LawHess's law allows us to combine reactions algebraically and then combine their enthalpy changes the same way.
- https://chem.libretexts.org/Courses/Los_Angeles_Trade_Technical_College/DMA_Chem_51_Su_19/2%3A_Beginning_Chemistry_(Ball)/07%3A_Energy_and_Chemistry/7.4%3A_Enthalpy_and_Chemical_ReactionsEvery chemical reaction occurs with a concurrent change in energy. The change in enthalpy equals heat at constant pressure. Enthalpy changes can be expressed by using thermochemical equations. Enthalp...Every chemical reaction occurs with a concurrent change in energy. The change in enthalpy equals heat at constant pressure. Enthalpy changes can be expressed by using thermochemical equations. Enthalpy changes are measured by using calorimetry.
- https://chem.libretexts.org/Bookshelves/Introductory_Chemistry/Beginning_Chemistry_(Ball)/07%3A_Energy_and_Chemistry/7.04%3A_Enthalpy_and_Chemical_ReactionsEvery chemical reaction occurs with a concurrent change in energy. The change in enthalpy, a kind of energy, equals heat at constant pressure. Enthalpy changes can be expressed by using thermochemical...Every chemical reaction occurs with a concurrent change in energy. The change in enthalpy, a kind of energy, equals heat at constant pressure. Enthalpy changes can be expressed by using thermochemical equations. Enthalpy changes are measured by using calorimetry.
- https://chem.libretexts.org/Courses/Western_Washington_University/Biophysical_Chemistry_(Smirnov_and_McCarty)/01%3A_Biochemical_Thermodynamics/1.03%3A_ThermochemistryIn this chapter we apply the first law of thermodynamics and the concept of enthalpy introduced in Chapter I.2 to chemical reactions. At standard state conditions we can use tabulated heats of formati...In this chapter we apply the first law of thermodynamics and the concept of enthalpy introduced in Chapter I.2 to chemical reactions. At standard state conditions we can use tabulated heats of formation to calculate the change in enthalpy for any reaction. At temperatures other than standard conditions we use the temperature dependence of the enthalpy to derive an expression for the change in enthalpy of a reaction at any temperature in relation to a reference temperature.
- https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Physical_Chemistry_(Fleming)/04%3A_Putting_the_First_Law_to_Work/4.05%3A_The_Joule-Thomson_EffectThe page explains the Joule-Thomson experiment and its significance in understanding gas cooling during expansion, which influenced refrigerator design. It also details how not all gases cool upon exp...The page explains the Joule-Thomson experiment and its significance in understanding gas cooling during expansion, which influenced refrigerator design. It also details how not all gases cool upon expansion, like hydrogen and helium, which can warm up. The Joule-Thomson coefficient (\(\mu_{JT}\)) determines this temperature change, generally calculated through the change of properties like pressure and enthalpy.
- https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Physical_Chemistry_(Fleming)/06%3A_Putting_the_Second_Law_to_Work/6.02%3A_Combining_the_First_and_Second_Laws_-_Maxwell's_RelationsThis page discusses the dependence of Gibbs and Helmholtz functions on variables like temperature, pressure, and volume, highlighting the integration of the First and Second Laws into a mathematical e...This page discusses the dependence of Gibbs and Helmholtz functions on variables like temperature, pressure, and volume, highlighting the integration of the First and Second Laws into a mathematical expression. It focuses on the development of Maxwell Relations, which arise from these combined laws and offer a powerful way to substitute partial derivatives to simplify thermodynamic analyses.
- https://chem.libretexts.org/Courses/Widener_University/CHEM_145%3A_FA22_Van_Bramer/06%3A_Thermochemistry/6.06%3A_EnthalpyIf a chemical change is carried out at constant pressure and the only work done is caused by expansion or contraction, q for the change is called the enthalpy change with the symbol ΔH. Examples of en...If a chemical change is carried out at constant pressure and the only work done is caused by expansion or contraction, q for the change is called the enthalpy change with the symbol ΔH. Examples of enthalpy changes include enthalpy of combustion, enthalpy of fusion, enthalpy of vaporization, and standard enthalpy of formation. If the enthalpies of formation are available for the reactants and products of a reaction, the enthalpy change can be calculated using Hess’s law.
- https://chem.libretexts.org/Courses/Westminster_College/CHE_180_-_Inorganic_Chemistry/13%3A_Chapter_13_-_s-Block_Elements/13.9%3A_Group_2/Chemical_Properties_of_Group_2/The_Thermal_Stability_of_the_Nitrates_and_CarbonatesThis page examines at the effect of heat on the carbonates and nitrates of the Group 2 elements (beryllium, magnesium, calcium, strontium and barium). It explains how the thermal stability of the comp...This page examines at the effect of heat on the carbonates and nitrates of the Group 2 elements (beryllium, magnesium, calcium, strontium and barium). It explains how the thermal stability of the compounds changes down the group.
