1. Lecture 314/20/05 Environmental Club - Cleanup day Saturday, April 23 rd at 11:00am Meet in front of Hagan on the lawn Sign-up sheet Final: Thursday May 5 th - 9 am

2. Isomers: Stereoisomers 1.Geometric (only square planar and octahedral) cis trans Different properties (color, solubility, melting point, etc)

3. Isomers: Stereoisomers 2.Optical: mirror images Octahedral complexes Same physical properties but rotate polarized light differently

4. Thermodynamics: study of energy and transformations Energy (capacity to do work) Kinetic energy (energy of motion) Thermal Mechanical Electrical Sound Potential Energy (energy from position or composition) Chemical potential energy Gravitational energy Electrostatic energy

5. Units 1 calorie (cal) energy required to raise the temperature of 1 g of water 1 °C 1 calorie (cal) = 4.184 Joule (J) KJ is normally more useful 1 Joule = 1 kg-m 2 /s 2 Calorie (Cal) Nutritional unit 1 Cal = 1000 calories = 1 kcal

6. 1 st Law of Thermodynamics Law of conservation of energy Energy in the universe is conserved System vs. surroundings vs. universe Internal energy Kinetic energy + potential energy Can’t find absolute energy, only change in energy ∆E = E final – E initial Positive ∆E  system has gained energy (endothermic) Negative ∆E  system has lost energy (exothermic)

7. Specific heat capacity (C) Quantity of energy to increase the temperature of 1 gram of a substance by 1 degree C (liquid water)= 4.184 J/g·K C (ice)= 2.06 J/g·K C (steam)= 1.84 J/g·K C (aluminum)= 0.902 J/g·K Molar heat capacity Quantity of energy that must be transferred to increase the temperature of 1 mole of a substance by 1 °C

8. Specific heat capacity (C) q = Cm∆T heat (J) Specific heat capacity (J/g·K) mass (g) Change in temperature (K)

9. Example 59.8 J are required to change the temperature of 25.0 g of ethylene glycol by 1 K. What is the specific heat capacity of ethylene glycol?

10. Heat transfer q gained + q lost = 0 q gained = - q lost 55.0 g of iron at 99.8°C is plunged into 225 g of water at 21°C. What is the final temperature? C (iron) = 0.451 J/g-K