PPT-5.2 Calorimetry and Enthalpy

Heat Capacity Specific Heat Capacity c the quantity of thermal energy required to raise the temperature of 1 g of a substance by 1C Units are in JgC Heat Capacity Specific heat capacity values can be looked up in tables. is the enthalpy change when one mole of a compound is formed from its constituent elements under standard conditions. . Enthalpy Change of reaction . is the enthalpy change that accompanies a chemical reaction in molar quantities expressed in a chemical equation. . Quick Review of Concepts. We have been introduced to heat producing (. exothermic. ) reactions and heat using (. endothermic. ) reactions. Heat is a measure of the transfer of . energy. from a system to the surroundings and from the surroundings to a system. 2. . Know and be able to account for the trends in reactivity with water. , the relative solubility of the hydroxides and sulfates. . The Trend . Hydroxides increase in solubility down the group.. Sulfates decrease in solubility down the group.. Fall, 2010 Indirect Calorimetry 1 Indirect Calorimetry Indirect Calorimetry CALORIMETRY The science that quantifies the heat release from metabolism is termed calorimetry . Figure 4.5 CALORIMETRY D n, For a solution prepared using 1 kg of solvent, water and m ()()HaqwMHaqHaq111 kg m==
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The chemical potential of the solvent in an aqueous solution is related to the molality of solute j, m () Physics 12 . Objectives. Define . specific heat capacity.. Solve problems involving specific heat capacities.. Explain the difference between solid, liquid, and gaseous phases.. Explain in terms of molecular behavior why temperature does not change during a phase change.. Enthalpy. Enthalpy (H)is the total amount of energy contained within a substance. Included all forms of energy, kinetic, potential…. Very difficult to measure all forms of energy within a substance, therefore a change in enthalpies is measured whenever a change occurs.. calorimetry Enthalpy changes in reactions Calorimetry and heat measurement Hess’s Law Heats of formation Learning objectives • Describe the standard state for thermodynamic functions &# g. recall the stages involved in the formation of a solid ionic crystal from its elements and that this leads to a measured value for the lattice energy (students will not be expected to draw the full Born-Haber cycles). Spontaneous Reaction. A reaction that occurs without outside intervention.. Once it occurs it can be fast or slow.. It can go to completion. (Recall the three products produced :. Precipitate (table F), gas, or water.). Jukka. . Pekola. , . Low. . Temperature. . Laboratory. Aalto . University. , Helsinki, . Finland. Calorimetry for . measuring the photons. Requirements for calorimetry on single microwave quantum level. Photons from relaxation of a superconducting qubit.. Enthalpy . is a state function . (the pathway does not matter) with . the symbol . H. ..  . H . = E . P V. E . is the internal energy of the system, P is the pressure of the system, and V is the volume of the system.. Reaction Energies. In our earlier discussions of calorimetry, we used . physical. sources of heat (hot metal slug). It is also possible to use . chemical. sources of heat (like hot packs and cold packs).. Enthalpy . is a state function . (the pathway does not matter) with . the symbol . H. ..  . H . = E + . P V. E . is the internal energy of the system, P is the pressure of the system, and V is the volume of the system..