Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,A Taste of Thermodynamics and Reaction Rates,A Taste of Thermodynamics and,1,Nature of Energy,Energy the ability to do work or produce heat.,Two basic forms of energy,Potential stored energy,Kinetic-energy of motion,Nature of EnergyEnergy the a,2,Law of Conservation of Energy,Energy can be converted from one form to another,but can not be created or destroyed.Also known as the 1 st law of Thermodynamics.,Law of Conservation of Energy,3,Heat versus Temperature,Temperature is an indication of the kinetic energy of an object.It also lets you know which way the energy will flow in relation to the surrounding objects.,If an object has a higher temp than its surrounding,energy will flow out of the object to the surroundings.,If an object has a temp lower than its surroundings,energy will flow into the object.,Heat versus TemperatureTempera,4,Heat,Heat is the measure of the amount of energy.,A Calorie is the metric unit of heat.It is the amount of heat needed to raise the temperature of one gram of water one degree Celsius.,The SI unit is a Joule.,1 calorie,=4.184 Joules,Heat Heat is the measure of th,5,Specific Heat-the amount of heat needed to raise the temperature of one gram of that substance one degree celsius.,A dietary Calorie,with a capital“C”is actually a Kilocalorie.,So a 2000 Calorie diet is really a 2,000,000 calorie diet.,So how do we measure Calories?,Specific Heat-the amount of h,6,Calorimeter,Calorimeter,7,Because we know the definition of a calorie,the mass of the water in the calorimeter and the temperature change.We can calculate the number of calories produced.,q,=c x m x,T,The way the book writes it.I prefer,H =c x m x T,Because we know the definition,8,Because you cant really measure heat content,only the heat change.I like,H as change in heat.,C is the specific heat of water.,M is the mass of the water.,T is the change in temperature.,See sample problem on page 524,Because you cant really measu,9,Heat of Reaction,Remember Heat of solution from last chapter?,Heat of reaction is just like it,the energy change that takes place during a chemical reaction.,(+)heat of rx,=endothermic,(-)heat of rx=exothermic,Heat of ReactionRemember Heat,10,Potential Energy Diagram,Potential Energy Diagram,11,Potential Energy Diagram II,Note:relate to heat and cold packs,Potential Energy Diagram IINot,12,Rates of reaction,How fast or how slow a reaction proceeds.,This can be explained using a model called the Collision Theory,Rates of reactionHow fast or h,13,Collision Theory,Like two cars in a very large parking lot slowly and randomly moving around.,What is the likely hood that they will react with each other?,They have to find each other,make contact,which is hard enough,and at the correct orientation to cause an accident that will exceed the insurance deductible,(threshold energy),Collision TheoryLike two cars,14,How can we increase the odds of an accident happening?,Increase the number of cars,(concentration)list various factors,increase the speed,(temperature),bigger cars,more,surface area,is easier to hit.,how well the vehicles are made a preus versus a BMW (nature of reactants),Demos would be good,How can we increase the odds o,15,Particle energy&Temperature,Particle energy&Temperature,16,Activation energy(threshold),Activation energy(threshold),17,Catalyst,a farmers inventory,A substance that speeds up a reaction,but is not affected by the reaction.,A chemical instigator,Catalysta farmers inventoryA,18,Energy of reaction,Energy of reaction,19,