Warm up (Sept 27) Lab 3 on desk all done, please! Homework Packet also out, please! AP Practice Problem on your own with equations sheets: This would be a 10 minute-long problem (from a recent exam!) #5 2016 practice exam – ionization energy and light – great question

Waves – a recap c = νλ E = hν Why does this equation make sense? What else is it useful for?

Bond breaking energy The bond strength of Cl2 is 242 kJ/mol. Find the wavelength of energy needed to break one Cl-Cl bond. What do we need to do??? Many steps! 4.94 x 10 -5 m (or 0.0494 mm) http://www.chemhume.co.uk/ASCHEM/Unit%201/Ch3Chemstr/Images%203/covalent_bonding_cl2.jpg

Cool Article! https://www.sciencedaily.com/releases/2017 /03/170313135050.htm

Solution Stoichiometry! How much 0.145 M HCl would you need to add to 3.15 grams of Zinc to react it fully? Start with a balanced equation! 664 mL

Practice Problem – solution stoich! 45.0 mL of 0.500 M iron (III) acetate is mixed with 110.0 mL of 0.350 M sodium hydroxide. Write the balanced chemical equation and the net ionic equation What is the theoretical yield of the reaction? If the percent yield is 120%, what was the actual (experimental yield)? Can you name a realistic source of error? Theoretical = 1.37 g Fe(OH)3 Actual = 1.65 g Source of error = too many spectator ions not rinsed out, rust, still wet

Lab 4 – Synthesis of Alum Putting a lot of Unit 1 into practice! Molarity Stoich Hydrates A couple of new techniques!! Crystallization Filtration using a buchner funnel – you’ll love it! Melting point test for purity? (If time) VERY DANGEROUS – aprons and gloves today ALL DAY (after school)

What is ALUM? Potassium Aluminum Sulfate Hydrate salt You’ll be finding the hydrate number next week https://en.wikipedia.org/wiki/Alum

NOW: Pre-lab 4 so we are ready to start after school on time! Purpose, data table, and lots of room for observations needed (three days of lab!) Pre-lab qs before you can start today! Groups: Keegan/Solhee, Mario/Luca/Gioia, Benedetta/Zefan, Thomas/Federico, Austin/Allan, Meher/William, Mattia/Alvaro

Homework Day 9 Zumdahl Homework (Webassign still isn’t figured out, so it’ll be paper this time) Chapter 4: 38, 39, 42, 44, 56, 58 We should be comfortable with 4.1-4.7 (check that you feel that way!) Unit 1 Test Next week Thursday!