2. Catalyst 1.If you have 2000 g of water and you heat it up from 10 o C to 70 o C, then what is the total heat produced in this process? The specific heat of water is 4.18 J/(g x o C). 2.If 980,000 J of energy are added to 6200 g of water at 291 K, what will the final temperature of the water be? The specific heat of water is 4.18 J/(g x o C) [CHALLENGE QUESTION] End

3. 100 o C Water Burn100 o C Steam Burn

4. Justify – TPS Why is it worse to be burnt by 100 o C steam than 100 o C water? Justify your answer with Word Wall vocab!

5. Lecture 7.4 – Latent Heats

6. Today’s Learning Target 7.7 – I can use the latent heat of phase change to calculate the amount of energy that is released or absorbed during a change of phase.

7. What are Latent Heats?

8. I. ΔH fusion and ΔH vaporization There is energy required to change phases ΔH fusion = Energy to change solid to a liquid. ΔH vaporization = Energy to change liquid to a gas. ΔH freezing = Energy to change liquid to a solid ΔH condensation = Energy to change gas to a liquid

9. II. Latent Heat Can calculate the amount of energy needed to convert a substance from one phase to another Latent Heat – The energy absorbed as a substance changes phases

10. ΔH of vaporization/condensat ion ΔH of fusion/freezing Latent Heats

11. How do you calculate latent heats?

12. I. Equation for Latent Heat m = mass of compound ΔH = Enthalpy values for phase changes (constants) Easy way to remember: Q equals maH! (The delta kinda looks like an A!)

13. Class Example You have a 2000 kg of ethanol. Calculate the energy you would need to turn solid aluminum into liquid. The ΔH fusion is 109 kJ/kg.

14. Table Talk You have 6342 kg of mercury. How much energy would be required to take mercury from liquid to a gas? The ΔH vaporization is 294 kJ/kg

15. Stop and Jot You have an ice cube of H 2 O that weighs 2000 kg and you melt it to liquid. How much energy does that require? The ΔH fusion is 334 kJ/kg.

16. SUMMARIZE

17. Checklist Manifesto! How do I know which equation to use?  Does it have specific heat?  Then use calorimetry!  Does it give you ΔH or ΔT  If ΔH then use q = mΔH  If ΔT then use q = m x C p x ΔT  Box the one it’s asking you to find!  Plug in the right numbers and solve!

18. Connect 4

19. Begin working on your “Homework 7.3” There will be an exit slip after this activity Work Time

20. Learning Log Assessment Rate yourself 1 – 4 on LTs 7.1-7.7

21. 1. You have 2000 g of water that is heated from 25 C to 100 C. What is the heat absorbed by this process. The specific heat of water is 4.184 J/(gxC) Exit Slip

22. Learning Log Assessment Rate yourself 1 – 4 on LTs 7.7

24. Test Thursday/Friday! Closing Time