PPT-Enthalpy Enthalpy is a measure of the total energy of a system.

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. Enthalpy. Unit . 11. Learning Objective. You should be able to . define and calculate the enthalpy . of a reaction.. You should be able to . identify. whether a reaction is . endothermic or exothermic . Enthalpy and Hess’s Law. Energy Changes in Chemical Reactions. Let’s take a typical reaction. CH. 4 . (g) + O. 2. (g) .  CO. 2. (g) + 2 H. 2. O (l). . This is an example of ‘burning a fossil fuel.’ This reaction releases energy! . 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. Internal Energy Equation. ΔE = Q + W = Q . + . PΔV. If the reaction is carried out at a constant volume (ΔV = 0) , then ΔE = Q. If volume is constant, any heat added or removed changes the internal energy. 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.. 12.1 Types of Enthalpy Change . 12.2 Born-Haber Cycles. 12.3 Enthalpy Changes – Enthalpy of Solution. 12.4 Mean Bond Enthalpy. 12.5 Entropy. 12.1 Enthalpy Change – Ionic Compounds. Learning Objectives:. Thermodynamics. is the study of energy and how it is interconverted.. First law of thermodynamics. – energy cannot be created or destroyed; it can only be converted from one form to another (. law of conservation of energy. Heat Capacity. Specific Heat Capacity (c): . the quantity of thermal energy required to raise the temperature of 1 g of a substance by 1°C.. Units are in J/g∙°C. Heat Capacity. Specific . heat capacity values can be looked up in tables. 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.. Lecture Presentation. © 20. 12. Pearson Education, Inc.. © 2012 Pearson Education, Inc.. Energy. Energy. is the ability to do work or transfer heat.. Energy used to cause an object that has mass to move is called . AP Chemistry. thermodynamics. : the study of energy and. its transformations. -- . thermochemistry. : the subdiscipline involving. chemical reactions and. energy changes . temperature.. Chapter. 4. Thermochemistry. Thermochemistry. is . the study of heat change in chemical reactions.. The . system. is . the specific part of the universe that is of interest in the study.. open. mass & energy. 2. nd. semester. Suggested Books:. An introduction to Chemical Thermodynamics by . Rastogi. and . Mishra. Physical Chemistry, . vol. 2 by K. L. . Kapoor. Physical Chemistry by Peter Atkins, Oxford University Press, Oxford. Thermochemistry. 1. st. Law of Thermodynamics- total energy of the universe is constant (p. 244). Definitions and State Functions. System. - a system is the part of the universe that is being studied. In Chemistry, this is often just a particular reaction (p. 243).