1. No category

Equations
nRT
n
P
 a 
V  nb
V 
2
ln
P2  vap  1 1 

  
P1
R  T2 T1 
Constants and Conversions
R  0.08206
atm  L
J
 8.314
K  mol
K  mol
K  oC  273.15
1 atm  760 mm Hg  1.013 bar
cal  4.184 J
J  Watt  sec
TABLE OF HEAT
CAPACITIES
Substance
C298[J/goC]
Lead (Pb)
0.128
Gold (Au)
0.128
Silver (Ag)
0.235
Copper (Cu)
0.385
Iron (Fe)
0.449
Aluminum (Al) 0.903
ethanol
2.42
Water (liquid) 4.18
pyrex
0.75
granite
0.79
sand
0.84
Hfus (water) = 6.02
kJ
mol
Hvap (water) = 40.7
kJ
mol
CHM136: General Chemistry II
Exam 1: Spring 2015
Name______________________________________
1. 10 pts. Perform the following conversions (use space to the right to show work):
294 K = __________ oC
18.2 kJ = __________ kcal
3655 kJ = __________ kWh
789 mm Hg = __________ atm
2.85 bar = __________ mm Hg
2. 10 pts. Calculate the total heat required to change 125 grams of liquid water at 25 oC to a vapor at 100 oC.
You may assume a constant 1.00 g/mL density for water. Circle your final answer and include units.
3. 10 pts. Using the table of heats of formation, calculate the enthalpy change (in kJ/mol) for the following:
2 NO( g )  O2( g )  2 NO2( g )
Circle your final answer.
4. 10 pts. A 65 gram mass of copper at 125 oC is added to 100. grams of water in a thermos at 22 oC. Given
enough time for the system to equilibrate and assuming no heat loss to the surroundings, what is the final
temperature of the mixture? Report your answer to the nearest degree and circle it.
5. 10 pts. An experimenter collects carbon dioxide gas over water at 30 oC. The total volume of water displaced
is 95.0 mL. The barometric pressure is 760 mm Hg in the laboratory. How many moles of carbon dioxide have
been collected?
6. 5 pts. An ideal gas confined to a steel vessel at a temperature of 298 K is at a pressure of 2.7 atm. If the
vessel is heated to a temperature of 375 K, what will be the resulting pressure? Circle your answer and be sure
to include units.
7. 5 pts. A mixture of oxygen and helium has a total pressure of 5.7 atm and is contained in a 1.0 L vessel at
298K. If the partial pressure of oxygen is 2.2 atm, what are the mole fractions of each gas in the mix?
8. 10 pts. List every kind of intermolecular force present in these substances:
N2
CH3CH2OH
CCl4
HCl
He
9. 10 pts. Which of these pairs would have a higher boiling point?
CH3CH2OH or CH3CH2SH
He or CH4
CH4 or CH3Cl
NaCl or MgO
CH3CH2CH2CH2CH2OH or CH3CH2OH
10. 10 pts. Complete the following phase diagram by identifying the three regions (solid, liquid, gas), the
sublimation line, the vaporization line, and the melting line. Also label the triple point and the critical point.
P
T
11. 10 pts. Calculate the boiling point of water on top of Mt Whitney (air pressure is equal to 0.60 atm).