1. Lecture 324/22/05 EARTH DAY Environmental Club - Cleanup day Saturday, April 23rd at 11:00am Meet in front of Hagan on the lawn Sign-up sheet Final: Thursday May 5th - 9 am Cancelled

2. QUIZ 1. Name the following compound: Fe(H 2 O) 4 Cl 2 2. What is the geometry of the compound? 3. What is a linkage isomer?

3. How much energy has a cup of coffee lost after it has cooled down to room temperature?

4. Changes in state Temperature stays the same during changes of state Gas/Vapor Liquid Solid ENERGY q = mass x constant q = moles x constant

5. Change of state constant??? Depends on two things: Identity of substance Which states are changing

6. Solid/Liquid Heat of fusion Solid  Liquid Endothermic ice  Water (333 J/g or 6 KJ/mol) Heat of crystallization Liquid  Solid Exothermic Water  ice (- 333 J/g or - 6 KJ/mol)

7. Liquid/Gas Heat of vaporization Liquid  Gas Endothermic water  water vapor (40.7 KJ/mol) Heat of condensation Gas  Liquid Exothermic vapor  Water (- 40.7 KJ/mol)

8. Solid/Gas Heat of sublimation Solid  Gas Endothermic Heat of deposition Gas  Solid Exothermic

9. What is the minimum amount of ice at 0 °C that must be added to a 340 mL of water to cool it from 20.5°C to 0°C? q water + q ice = 0 C water m water ∆T water + m ice ∆H fus = 0 (4.184 J/K-g)(340 g)(0°C - 20.5°C) + (333 J/g)m ice = 0 m ice = 87.6 g

10. A rainstorm deposits 2.5 x 10 10 kg of rain. Calculate the quantity of thermal energy in joules transferred when this much rain forms. (∆H vap = - 44 KJ/mol) Exothermic or endothermic? q = 2.5 x 10 10 Kg x (10 3 g/kg) x (1 mol/18 g) x -44 KJ/mol q = -6.1 x 10 13 KJ Exothermic