The flow of energy heat
This presentation is the property of its rightful owner.
Sponsored Links
1 / 10

The Flow of Energy – Heat PowerPoint PPT Presentation


  • 84 Views
  • Uploaded on
  • Presentation posted in: General

The Flow of Energy – Heat. Chapter 17.1. Warm Up. What happens to the heat from the lava?. Why does lava cool more quickly in water than on land?. Introduction to Thermochemistry.

Download Presentation

The Flow of Energy – Heat

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


The flow of energy heat

The Flow of Energy – Heat

Chapter 17.1


Warm up

Warm Up

What happens to the heat from the lava?

Why does lava cool more quickly in water

than on land?


Introduction to thermochemistry

Introduction to Thermochemistry

  • Thermochemistry (or Thermodynamics) is the study of heat, energy, and temperature changes that occur during chemical reactions (One of the main courses of study in Physical Chemistry)

  • Law of Conservation of Energy (1st Law of Thermodynamics) – The law of conservation of energy states that energy may neither be created nor destroyed. Therefore the sum of all the energies in the system is a constant. (Whether a reaction flask or the universe


Temperature vs heat

Temperature vs. Heat

  • Temperature is the measure of the average kinetic energy of the particles in a substance

    • Measure using a thermometer

    • Rises when heat is added

    • Falls when heat is removed

  • Heat(q) is the energy that is transferred between two objects

    • Cannot be measured directly

    • Can only detect the changes caused by heat

HOT

COLD


Thermochemical reactions

Thermochemical Reactions

  • System – reactants and products

  • Surroundings – the reaction container


Exothermic vs endothermic

Exothermic vs. Endothermic

Exothermic

Endothermic

Heat

Heat


Measuring heat

Measuring Heat

  • The Joule (J) is the SI unit of heat and energy

  • The calorie (cal) is also used to measure heat capacity and is defined by the amount of heat needed to raise the temperature of 1g of pure water by 1C

  • 1 J = 0.2390 cal1 cal = 4.184 J

  • NOTE: The energy contained in food is measured in Calories (Cal) = 1000 calories = 1 kcal


Heat capacity vs specific heat

Heat Capacity vs Specific Heat

  • Heat capacity is the amount of heat needed to raise the temperature of a substance by 1C

    J/C or J/K

  • Specific heat capacity (C) is the amount of heat needed to raise the temperature of one gram of a substance by 1C

    J/gC or J/gK


Examples of specific heat capacities

Examples of specific heat capacities


Cool down

Cool Down

Which of these pictures contains more heat?

C = q / m xDT

q = C x m xDT


  • Login