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3/4/2013 Standards: 4 (Gases and their Properties)OBJECTIVES: ● Prepare for Quiz 3.3 (Ch 13.1 & 14), doing HW in class ● Use responder questions to review for Quiz 3.3 .DO NOW: 1. If P = 705 Torr; V = 85 mL; T = 115 °C . Find moles of gas. 2. If the gas is methane CH4 , how many grams will that be? HOMEWORK: 1. Std Test Pract p. 451 6 (a), 7 (c), 8 (d), 9 (c), & 10 (a) (5 pts) Std 4 2. Help Sheet - 1/2 sheet 8.5 x 11" paper, one side only. Name, 3/5/13,
and period in top right corner as paper looks wider than tall. Recommended info: combined gas law, PV = nRT (R = 0.0821 andreq'd units for each variable), 22.4 L = 1 mol of any gas at STP, what STP means. Dalton's Law
=======================================================
next page for stamping
With all the stuff we had to do today and a minimum day schedule, no time for quizzes or responders. Tried to do too much.
BASKET (stamped): Journal 3/1 1. Ch 14 Assess p. 448-449 88 (1. 1.6 atm; 2. 190 K; c. 510 mmHg;
d. 0.96 atm), 90 (1.17 atm), 92 (74.8 kPa), 94 (5.91 x 104 L), 96 (34 L), 98 (2.93 g/L) (5 pts) Std 4
2. Std Test Pract p. 451 1-5 (5 pts) Std 4
BLACK TRAY: Boyle's Law Lab - (15 pts) Std 4
Period 2 only
Student Paths -
Complete survey card and return tomorrow (5 pt assignment)
3/5/2013 Standards: 4 (Gases and their Properties)OBJECTIVES: ● Prepare for Quiz 3.3 (Ch 13.1 & 14), with responder questions.DO NOW: 1. If P = 2.70 kPa; V = 7.50 L; T = 15.0 °C . Find moles of gas. 2. If the gas in #1 above is Ar, how many grams will that be? HOMEWORK: 1. Study for Quiz 3.3, coming tomorrow Wed 3/6======================================================= BASKET (stamped): Journal 3/4 1. Std Test Pract p. 451 6 (a), 7 (c), 8 (d), 9 (c), & 10 (a) (5 pts) Std 4
BLACK TRAY: Extra Credit (from Practice Quiz 3.3) (double credit)
Help Sheet - STAMPED AT YOUR DESK
RESPONDERS
TOMORROW
Good lesson plan - worked well for full period. However only got to responder question 4 most classes
Announcements:
1. Ch 14 Quiz 3.3 coming tomorrow Wed 3/6 (60 pts)2. Mem Ions 4 (4th time) Fri 3/8 --------- (40 pts) 3. Labs (all of them for Ch 13 & 14) WILL NOT
BE EXCUSED - MUST BE MADE UP BY Friday 3/8
4. Extra Credit - Practice Quiz 3.3 (Ch 13.1, 14.1-14.4). Still available. One pt ex cr for each 4 problems
worked out. a. calculation problems: given, find, calculation, and
correct answer circled. b. non-calculation problems: copy complete
question, show correct answer (written out, not just the letter). Show page # from text where the answer could be explained from, and a complete explanation as to what is on that page to help and why it works.
Review
P1V1 n1T1
P2V2 n2T2
=
PV = nRT
P any unit OKV any unit OKn any unit OKT only Kunits must be same on ea. side
P atm onlyV L onlyn mol onlyR = 0.0821T K only
22.4 L = 1 mol @ STP
Ideal Gas Law
Combinedgaslaw
PT = P1 + P2 + P3 ..... Pn
Dalton's Lawall variables must be the same unit of measure
can use instead
of PV = nRT IF
This slide was an excellent review.
Rate A
Rate B=
Molar mass B
Molar mass A
Graham's Lawof Effusion /Diffusion
For today's quiz questions, all students have responders where they respond to each question. Individuals will be called on to explain why correct, for ex cr for their group.
1 Why are the the pressure calculations coming out the same for molecules of different sizes?
A molar mass is part of PV = nRTB they aren't, mass of molecule mattersC lighter molecules hit side of container more often than heavier molecules, resulting in their exerting the same amount of pressure on the inside of the container D pressure of all gases is constant and doesn't change
2 If you have 1 mol ea of 5 different molecules, how much more pressure (P) will the 5 exert together than only one?
A 2 times more P
B 5 times more P
C this cannot be determined with gas laws
D 3 times more P
Which law is used to solve the above problem?A. Boyle's LawB. Dalton's LawC. Charles' LawD. Combined Gas LawE. PV = nRTF. Gay-Lussac's Law
3 Does the molecule mass affect the pressure it will exert on the inside of the vessel it is in?
Yes
No
4 Calculate the pressure, if 1.50 mol of CH4 in a vessel of 30.0 L, at a temp. of 100. °C.Round to 3 sig. figs (no spaces & enter unit of measure)
Given: Find:n = 1.50 mol P = ?V = 30.0 LT = 100. °C + 273 = 373 K
PV = nRT
P (30.0 L) = (1.50 mol) x (0.0821) x (373 K)
(1.50 mol) x (0.0821) x (373 K)
(30.0 L)P = P = 153 atm
5 Given the conditions shown, which gas law will you need to use? (problems from text)
A Combined Gas Law
B Ideal Gas Law
p. 433 32, 33p. 432
p 44888 a-d90929496 98
p 4516-10
3/6/2013 Standards: 4 (Gases and their Properties)OBJECTIVES: ● Check for understanding of Ch 13 & 14 with Quiz 3.3.DO NOW: 1. Clear desk and floor of everything except: Help Sheet, scratch paper,
eraser, pencil, calculator.HOMEWORK: 1. SN Ch 15.1 p. 199-203 (5 pts) Std 6======================================================= BASKET (Turned in): 1. Pract Quiz 3.3
Put papers into 5 stacks
Help Sheetsscratch
The following in order with smallest # on top:
quizzesscantroncharts
Spread so #'s show
3/7/2013 Standards: 6 (Solutions)Objectives: ● Students will be able to solve Henry's Law Problems for HW ● Demo - gas solubility & HOW EQUILIBRIUM is reached (demo).DO NOW: 1. define Henry's Law (equation) and what S & P mean 2. List the 3 factors for each that affect rate of
(a) solvation & (b) solubility? (total of 6 factors) (see p. 456 & 458)HOMEWORK:b 1. Ch 15.1, Practice Prob, p. 461 1-2, Assess. 3 & 5 (2 pts) Std 6 2. Ch 15 Assess, p. 484 64-68 (3 pts) Std 6=========================================================STAMPS: ● Journal 3/5 (day before Quiz 3.3, working on Quiz Review) 1. SN Ch 15.1 p. 199-203 (5 pts) Std 6
show example firstshake clear soft drinkbottle
/
Henry's Law allows chemists to figure out how much CO2 can be dissolved in water
H2O(l) + CO2 (g) <---> H2CO3 (aq) <---> H1+
(aq) + HCO3
1-
(aq)
Higher Pressure MORE SOLUBILITY====>
directly proportionalP & S
Henry's Law
S1 S2 P1 P2
=
S =
solubility (g/L)pressure (any unit OK)
P =
directly proportionalP & S
Example Problem - Henry's Law
3/8/2013 Standards: 6 (Solutions) Objectives: ● Check for understanding Mem Ions Quiz 4 (4 x) ● Student will be able to do simple percent by mass problems.DO NOW: 1. Given 3.00 mol CO2 , in 11.50 L H2O, at 705 Torr, What will the new
pressure be when an additional 8.75 mol CO2 is added to the vessel? (Henry’s Law) Ans: 2760 Torr (Hint: mol/L works for S)
2. p. 463 #8 (this is percent by mass – see top of p. 463) Ans: 3% (show how to get here)
HOMEWORK: 1. App A, p. 880 1-2 (1 pt) Std 6 2. Ch 15.2 p. 464-465 PP's 11-16 (4 pts) Std 6 3. HANDOUT TODAY - What Are Solutions - Tutorial Ch 15.1 Std 6===========================================================STAMPS: ● Journal 3/7 1. Ch 15.1, Practice Prob, p. 461 1-2, Assess. 3 & 5 (2 pts) Std 6 2. Ch 15 Assess, p. 484 64-68 (3 pts) Std 6
Let's do this again next week.
1. Given 3.00 mol CO2 , in 11.50 L H2O, at 705 Torr, What will the new pressure be when an additional 8.75 mol CO2 is added to the vessel? (Henry’s Law) Ans: 2760 Torr (Hint: mol/L works for S)
2. p. 463 #8 (this is percent by mass – see top of p. 463) Ans: 3% (show how to get here)
http://group.chem.iastate.edu/Greenbowe/sections/projectfolder/flashfiles/thermochem/solutionSalt.html
SOLVATION ANIMATION
1. agitation
2. increase surface area
3. temperature
Demo - see videomade in classyesterday
Units of measure in Henry's Law
S (solubility)g/L g/mL mol/L mol/mL (or any unit of volume besides L or mL)
P (pressure)atm, mmHg, Torr, kPa, Pa, psi
(any unit of pressure is OK)
m = (milli-) = 1
1000
How to derive equality with prefixes
What is 1 mL equal to in terms of L ?
1
1000mL = L x 10001000 x
1
1000mL = L x 10001000 x
1000 mL = 1 L
1
1000mL = L
k = (kilo-) = 1000
1 kg = 1000 g
How to derive equality with prefixes
What is 1 kg equal to in terms of g ?
Summary
Find value of prefix
Substitute the value of the prefix
6 What is the value of S if 25.0 g of gas is dissolved in 1.00 L of water?
Number only3 sig figs onlyno units of
measure
7 What is the solubility of a gas if 25.0 g of the gas will dissolve in 1.00 L of water.
Number only3 sig figs onlyno units of
measure
p. 463
possible solutes: a. salt (NaCl)b. sugar (sucrose)c. MgCl2 d. C (smaller portion of steel)e. paint pigments
possible solvents:f. waterg. iron (Fe major portion of steel)h. laquer thinner
`
8 Connect possible solutes to possible solvents
A salt
B sugar
C MgCl2
D C
E paint pigments (can pour down sink)
(cannot poud down sink)
F water
G iron
H lacquer thinner
9 What is the percent by mass of salt in a solution that contains 13.0 g of salt (solute) in 52 g of water (solvent)?
3 sig figsno units of measuredo not use %
at end of #
What is the percent by mass of salt in a solution that contains 5.0 g of salt (solute) in 25 g of water (solvent)?
3 sig figsno units of measureuse % at end of #
First Problem:
MASS OF SOLUTION = 13.0 g (solute)+ 52.0 g (solvent)------------- 65.0 g (solution)
Second Problem:
MASS OF SOLUTION = 5.0 g (solute)+ 25.0 g (solvent)------------- 30.0 g (solution)
10 Answer?