# Heat

## Heat

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
##### Presentation Transcript

1. Heat Investigation 5 part 3

2. EQ. How are changes in matter accompanied by changes in energy? • We have learned a great deal about this but there is more……

3. Today’s Focus • LEQ 21 Explain how to calculate the energy transferred from the hot water particles and the energy gained by the cold water particles. Discuss their relationship.

4. What is a calorie? • Open lab manual to page 48 “Calculating heat in Calories A” • Read information

5. Is there a pattern? • Change in temperature • ΔT=Tfinal – Tinital • Calculate calorie • Mass X ΔT = cal

6. Cal= • Cal = m X ∆T • Calories = mass X change in Temperature

7. A Heat Transfer Experiment • Last time we mixed water because we wanted to find out what temperature the final mix would be. • Today, I want to find out how much heat transferred from the hot water to the cold water and how much heat transferred to the cold water during the mixing.

8. Heat Transfer • Open to Lab Manual page 51 • Information/Data to enter • Columns 1-6

9. Mass • What is the relationship between mass and volume of water? • 1 mL = 1 cm3 = 1 g Mass volume This is only true for water

10. Experiment Procedure • Get 50 mL of hot water in one foam cup and 50 mL of cold water in second foam cup • Decide on the mass of hot water and the mass of cold water you will use. (need to be the same) • Measure the water with the graduated cylinders.

11. Procedure • Record their masses and starting temperatures in the table • Immediately pour the cold water and the hot water in the third foam cup. Put that foam cup into a 500 mL cup for stability • Quickly measure and record the final temperature.

12. Remember • Act quickly after you record the starting temperature • Immediately mix the samples and take the final temperature • You have 10 minutes! • Clean Up

13. CLEAN UP • Dump water in sink • Dry all materials completely • Return tray with all materials

14. RESULTS • What happened when you mixed the hot and cold water? • The mixture reached a temperature that was between the hot and cold water temperatures.

15. Results- • What caused the kinetic energy to change? • Energy (heat) transfer as a result of particle collisions. Energy transferred from hot water particles to cold water particles until the kinetic energy was the same for all the particles

16. Results-- • Did energy transfer from the hot water or from the cold water? • Energy transfers from the particles in the hot water. Energy flow is always from higher kinetic energy to lower kinetic energy.

17. Groups TPS • How many calories were transferred from the hot water? • How many calories were transferred from the cold water? • What does that tell you about energy transfer?

18. Conservation of Energy • Energy is conserved • The amount of energy in a system is always the same • No energy is ever created, and no energy is ever destroyed. • Energy is transferred.

19. Energy transfer • From one place to another • From one kind of energy to another kind of energy

20. Equilibrium • Hot and cold mix and particles collide • Energy transfers from high energy particle to low energy particle (from hot to cold from fast to slow) • Transfer continues until the volume of water is all moving the same speed with same amount of kinetic energy • The number of particles losing energy = the number of particles gaining energy (energy lost = energy gained) • System is balance, no net energy transfer equilibrium is reached temperature holds steady.

21. Class work • Complete LM page 52-53 • Mid Summative TEST Wednesday