Friday, December 10, 2010

The class period started out looking at the blog from the previous night. Mr Henderson then had the class take out the unit 6 packets.

To answer the following problems one of five equations must be used.

1)P*V=n*R*T
(R=0.08206 L * atm/mol * k)
P=pressure=force/area, force=cumulative force from all collisions of particles with container walls.(pounds/inch2=psi, atmosphere=atm, millimeters of mercury=mmHg, torr)

V=volume(liters,mL)

n=number of moles

T=temperature= measure of average kinetic energy or KE (C or kelvin). Kelvin(K)=C + 273

2)V1/T1=V2/T2
(when n and P are constant)

3)P1* V1= P2* V2
(when n and T are constant)

4)P1/T1= P2/T2
(when n and V are constant)

5)[P1*V1]/T1=[P2*V2]/T2

Page#9 number 1

1) V1= 16.9 V2=?
T1=25C (25+273=298), 298K T2=268K

Since the information given contains temperature and volume the next step is to look at which of the five equations contains temperature and volume and the equation is V1/T1=V2/T2

16.9/298=V2/268

V2=15.198 Liters

Page #10 number 7

7)V1=412 mL V2=663
P1=1.00 atm P2=?

Since the information given contains volume and pressure the equation for this problem is P1*V1=P2*V2

412*1=663*P2

P2=0.621 atm

Page #11 number 15

15) P1=2.50atm P2=?
T1=5C(5+273=278), 278K T2=650C(650+273=923), 923K

P1/T1=P2/T2

2.5/278=P2/923

P2=8.30 atm

Page #13 number 26 and 32

26) V1=18.5 L V2=?
P1=85.5 kPa P2=1atm, 1atm=101.3kPa
T1=296 K T2=273 K

[P1*V1]/T1=[P2*V2]/T2

[25.5kPa*18.5L]/296 K=[101.3kPa*V2]/273 K

V2=14.4L

32)V1=5.25L
T1=23C(23+273=296), 296K
P1=8.00 atm
n=?
m=?

P*V=n*R*T n=[P*V]/[R*T]

n=[8.00 atm*5.25L]/[0.08206L*atm/mol*K *296 K]=1.73 mol

m=1.73 mol CO2*[44 gCO2/1 mole CO2]=76.1 g

The class period ended with Mr. Henderson making ice cream for the class.
HW:2 webassigns due Monday and test Friday