Do Now & Agenda Take out HW to be checked Today: Unit 2 Test FRI 9/18 Solutions Mini Lab Chemical and Physical Properties (just the first page front and back) Unit 2 Test FRI 9/18 Unit 1 Test Corrections due MON 9/21

Solutions Mini Lab Fill in all the ____ mL with “50.0 mL” You must SHOW ALL WORK first. When ready, call me over for the chemical you need to make your solution.

Key Questions: 1. According to the models above, which property (or properties) is a physical property? Mass Boiling point 2. According to the models above, which property (or properties) is a chemical property? flammability

Key Questions 3. In the example of measuring mass, a) what substance do you start out with before the mass is measured? aluminum b) what substance do you end up with after the mass is measured?

Key Questions 4. In the example of measuring boiling point, water a) what substance do you start out with before the boiling point is measured? water b) what substance do you end up with after the boiling point is measured?

Key Questions 5. For questions 3 and 4, did you end up with the same substance or a different substance from what you started with after you measured the mass or boiling point? Same substance

Key Questions 6. Based on model 1 and your answer to the questions above, how would you describe what a physical property is?

Key Questions 7. In the example of measuring flammability, a) what substance do you start out with before the flammability tested? wood b) what substance do you end up with after flammability is tested? ashes c)Did you end up with the same substance or a different substance from what you started with after you tested flammability? different substance

Key Questions 8. Based on model 2 and your answer to question 7, how would you describe what a chemical property is?

Definitions Physical Property=a property of matter that can be measured or observed without changing the chemical composition of the substance Ex: mass, melting and boiling point, Solubility (ability to dissolve in something)

Definitions Chemical Property=a property of matter that can only be measured or observed by changing the chemical composition of the substance Ex: Flammability Reactivity (whether the substance reacts with another substance)

Practice Identify the following as either physical properties (P) or chemical properties (C) 1. ____blue color 2. ____density 3. ____solubility 4. ____reacts with acid 5. ____volume 6. ____melting point 7. ____reacts with water to form a gas 8. ____hardness P P P C P P C P

Intensive vs. Extensive Properties Intensive Property: does NOT depend on how much of the substance there is Extensive Property: depends on how much of the substance there is