Presentation on theme: "2/25/2013 Standard: 4 (Gases and their Properties) OBJECTIVES: ● Complete "Discovering direct & inverse in PV = nRT - Mini-Lab" ● Students will understand."— Presentation transcript:
2/25/2013 Standard: 4 (Gases and their Properties) OBJECTIVES: ● Complete "Discovering direct & inverse in PV = nRT - Mini-Lab" ● Students will understand the specific units of measure in PV = nRT DO NOW: 1. Read lab (today's handout) silently to yourself. HOMEWORK: 1. Ch 14.3 PP's p. 437 41-45 (5 pts) Std 4 =========================================================== BASKET (Stamped): Journal 2/22 (Dalton's Law Lab) 1. SN Ch 14.2 p. 190, Ch 14.3 p. 193-195 (3 pts) Std 4 2. Appendix A p. 879 8 & 9 (2 pts) Std 4
Discovering direct vs inverse in PV = nRT - Mini-Lab http://mrwiggersci. com/chem/Labs/La b-Gas-Sim-PVnT- relations-direct-or- inverse.pdf
PV = nRT ----- Ideal Gas Law P - atm V - L n - mol (never g) R = 0.0821 (don't bother w unit) T - always K PV nT Always use the following units when calculating anything with PV = nRT see p. 435 for units used for R, which requir e you use differe nt units from what you see above
2/26/2013 Standards: 4 (Gases and their Properties) OBJECTIVES: ● Students will be able to predict how ideal (accurate) an Ideal Gas Law calculation will be based on the conditions. ● Students will be able to use STP in gas law calculations DO NOW: 1. p. 437 41-45 HOMEWORK: 1. Ch 14.2 PP's p. 432-433 24 - 33 (5 pts) Std 4 =========================================================== BASKET (turned in): Journal 2/25 1. Ch 14.3 PP's p. 437 41-45 (5 pts) Std 4
Students having problems solving for an unknown, this is helpful. Have students solve for unknows in abcde letters, then use PV=nRT to apply it.
PV = nRT IDEAL GAS LAW What conditions make it most accurate? high temperature low pressure Not 100% accurate? Why? Intermolecular forces exist!!!!!! Do intr o to this by sho win g ten nis ball and golf ball s, tell the m the y wo n't beli eve you but the y act uall y attr act eac h oth er. Mol ecu les do the sa me thin g, bot h by gra vity and if the y are pol ar, by ma gne tis m. Sh ow ma gne ts, fast mot ion and slo w mot ion to de mo tem p hig h ma kes fast er mot ion and pre ssu re low allo ws mo re sep ara tion red uci ng attr acti ve forc es bet we en mol ecu les of gas.
a. 3.00 mol O 2 at STP has what volume? b. 8.00 L Ar at STP has how many moles? Guided Practice
p. 432 PP's 24 - 28 Show givens, find, and gas law you will use to solve. Work in groups of 4. Ex Cr for each group called on if the person called from the group can give and understand the problem called on. Extra Credit/ sentences
ANNOUNCEMENT If you have missed any of the labs for Ch 14 (see website) because you were absent or just didn't turn them in, you are still responsible to make these up. There are three counting the Boyle's Law lab you will be turn in next Monday. All labs must be made-up by Friday of next week
Boyle's Law Lab & simulator http://mrwiggersci.com/ chem/Labs/lab_Boyle_ Law-use-gas-sim.htm Go to computers and see if you can make the simulator work. This will be due on Monday 3/4/13. Go to Learning Center > Labs > Ch 14 > Boyle's Law Lab Try 2 different volumes and see what the pressures are. DEMONSTRATION OF SIM FIRST - then: This lab will be due on Monday 3/4/13
Charles Law - demonstration and simulator - demo sim and bottles in & out of hot water http://group.chem.iastate.ed u/Greenbowe/sections/proje ctfolder/flashfiles/gaslaw/cha rles_law.html
Balanced chemical equations give you 2 ratios! 1. mol (as before) 2. volume Volume and mole relationship is DIRECT because: 1 mol of any gas is will occupy 22.4 L of volume at STP
This also means: as long as the gases you are comparing are under the SAME conditions, this relationship exists.
So, this applies to all problems on p. 441 and p. 443
2/28/2013 Standards: 4 (Gases and their Properties) OBJECTIVES: ● Students will be able to solve stochiometry problems of volume - mass ● Students will be able to do concept maps for g A ---> L B DO NOW: 1. Balance this equation. __KClO 3 ----> __O 2 + __KCl 2. Draw a concept map to figure out how many liters of O 2 can be created form 29g KClO 3 at STP. 3. Show given, find, and then solve the problem. HOMEWORK: 1. Ch 14.4 PP's p. 443 61 - 64 and Assess 65 - 67 (5 pts) Std 4 =========================================================== BASKET (turned in): Journal 2/27 1. Ch 14.4 PP's p. 441 56-59; p. 443 60 (5 pts) Std 4