PPT-Thermochemistry Energy change that occurs during a chemical reaction and/or changes in

A form of energy Flows from warmer objects to cooler objects Represented by the variable q Measured by units calorie or joule 1 J 02390 cal 4184 J 1 cal 1000 cal 1 kilocalorie . #1: What happens to a substance when a chemical change occurs?. #2: What are some signs of a chemical change?. Bell Ringer: Tuesday 10/1/13. Read the paragraph below and determine the main idea. Then, write and answer the questions. Heat. Transfer and Specific Heat. Energy Changes in Chemical Reactions. Calculating . ∆H. Heat. Definition. The. energy transferred between samples of matter due to differences in their temperature.. Chapter 16 page 500. A. . ThermoChemistry. Introduction. Every chemical reaction causes a change in energy. Endothermic or exothermic. Thermochemistry – study of the transfer of energy as heat that happens during chemical reaction and physical changes. EVIDENCE of a CHEMICAL REACTION . (aka a . CHEMICAL CHANGE. ). . . . . . T. he decomposition of hydrogen peroxide H. 2. O. 2. . !!. 2 H. 2. O. 2. . . 2 H. 2. O + . O. 2. http. ://. www.youtube.com/watch?v=4N0m95PExHY. BY NISH DILLON. PRETTY EYESZ. http://www.chemistryexplained.com/images/chfa_01_img0184.jpg. Chemical Reaction basics. Chemical Reaction- When substances change chemically to form a new substance.. 1. Forms new bonds between atoms.. INTRODUCTION. All reactions require energy to break bonds in the reactants, and all reactions give off energy when new bonds form to make products. The difference in energy required to break the bonds and to make the new bonds can tell you whether the reaction is endothermic or exothermic. . Thermochemistry. Energy absorbed or released as heat in a chemical or physical change is measured in a . calorimeter. .. In some calorimeters, known quantities of reactants are submersed in water and combusted. The energy given off is noted by the temperature change in water.. Physical Property. Physical property = a characteristic of matter that can be . observed or measured . without changing the identity of the substance. . Ex: . mass volume . density hardness. color malleability. The key words are emphasized in bold . and there is a list of them at the end of the presentation. . Chemical Reactions. When a chemical reaction occurs, new substances (called . products. ) form from the substances taking part in the reaction (called . Define. . temperature. and state the units in which it . is measured.. Define. . heat. and state its units.. Perform. specific-heat calculations.. Solve. . problems involving enthalpies of reaction, enthalpies of formation, and enthalpies of combustion.. All. chemical reactions either release or absorb energy. . The energy can take many forms: . HEAT. , . LIGHT. , . SOUND. , and . ELECTRICITY. . Chemical . bonds. are the source of this energy. . Chemical Reactions. Chemical reactions occur every minute of every day. . Some are very fast, such as the reaction of sodium with water. . Others are very slow, such as iron rusting. . Some are somewhere in-between, such as milk going sour. . Nikhil . Gopalkrishnan. (From presentation of Chen, Doty, . Soloveichik. , Deterministic Function Computation with Chemical Reaction Networks.). (From presentation of Chen, Doty, . Soloveichik. , Deterministic Function Computation with Chemical Reaction Networks.). Change. First Law of Thermodynamics. Heat . (q. ). ,. work (. w. ) and internal energy (. E. ). Calculation of heat gained or lost by system. Calorimeter for measuring heat exchange (between system and surrounding;.