A-Taste-of-Thermodynamics-and-Reaction-Rates：一味的热力学和反应速率课件

1、A Taste of Thermodynamics and Reaction RatesA Taste of Thermodynamics and Nature of EnergyEnergy the ability to do work or produce heat.Two basic forms of energy Potential stored energy Kinetic - energy of motionNature of EnergyEnergy the aLaw of Conservation of Energy Energy can be converted from o

2、ne form to another, but can not be created or destroyed. Also known as the 1 st law of Thermodynamics. Law of Conservation of Energy Heat versus TemperatureTemperature 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 surroun

3、ding 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 TemperatureTemperaHeat Heat is the measure of the amount of energy.A Calorie is t

4、he 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 JoulesHeat Heat is the measure of thSpecific Heat- the amount of heat needed to raise the temperature of one gram of that substance one d

5、egree 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 hCalorimeterCalorimeterBecause we know the definition of a calorie, the mass of the water in the calorim

6、eter 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 preferH = c x m x T Because we know the definitionBecause you cant really measure heat content, only the heat change. I like H as change in heat.C is the specific heat of wa

7、ter.M is the mass of the water. T is the change in temperature.See sample problem on page 524Because you cant really measuHeat of ReactionRemember 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 = endo

8、thermic(-) heat of rx = exothermicHeat of ReactionRemember Heat Potential Energy DiagramPotential Energy DiagramPotential Energy Diagram IINote: relate to heat and cold packsPotential Energy Diagram IINotRates of reactionHow fast or how slow a reaction proceeds.This can be explained using a model ca

9、lled the Collision Theory Rates of reactionHow fast or hCollision TheoryLike 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 orient

10、ation to cause an accident that will exceed the insurance deductible(threshold energy)Collision TheoryLike two cars How can we increase the odds of an accident happening?Increase the number of cars ( concentration ) list various factorsincrease 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 goodHow can we increase the odds oParticle energy & TemperatureParticle energy & TemperatureActivation energy (threshold)Activation energy (threshold)Catalysta farmers