2nd Semester Review Problems
1. If 4.00 moles of Helium at a pressure of 5.4 atmospheres occupy a volume of 120 liters,
what is the temperature?
2. Calculate the pressure in a 212 Liter tank containing 23.3 kg of argon gas at 25.0°C?
3. What mass of CO2 is needed to fill an 80.0 L tank to a pressure of 150.0 atm at 27.0°C?
4. When filling a weather balloon with gas you have to consider that the gas will expand
greatly as it rises and the pressure decreases. Let’s say you put about 10.0 moles of He
gas into a balloon that can inflate to hold 5.00 x 104 L. Currently, the balloon is not full
because of the high pressure on the ground. What is the pressure when the balloon
rises to a point where the temperature is -10.0°C and the balloon has completely filled
with the gas?
5. If you were to take a volleyball scuba diving with you what would be its new volume if it
started at the surface with a volume of 2.00L, under a pressure of 752.0 mmHg and a
temperature of 20.0°C? On your dive you take it to a place where the pressure is 2943
mmHg, and the temperature is 0.245°C.
6. Valence electrons are the key to atoms bonding with each other. In the two types of
bonding how are they bonded differently?
 An ionic bond valence electrons…

A covalent bond valence electrons…
7. What is the octet rule in either ionic or covalent bonding?
8. In covalent bonding electrons are not always shared equally. What is a polar bond and
how can we tell whether or not a bond is polar or non-polar?
9. Lewis structures help us keep track of bonding electrons and lone pairs (electrons not
involved in bonding). Draw the Lewis structures for the following molecules.
a)
H2
c)
N2
b)
O2
d)
ClF
10. Use the heating curve below. Discuss what is happening at each of the five different
areas on the graph. What is the approximate melting point and boiling point of the
substance?
11. The boiling points of the noble gases are He (-272ºC), Ne (-246 ºC), Ar (-186 ºC), Kr (152 ºC), Xe (-107ºC) and Rn (-62 ºC). Discuss the trend in boiling points and explain
why they change in this manner.
12. Calculate the liters of 0.500 M NaCl needed to react with 375 mL of 0.200 M AgNO3.
AgNO3(aq) + NaCl(aq)  AgCl(s) + NaNO3(aq)
13. Calculate the mass of BaSO4 formed when 25.0 g of BaCl2 is added to 0.875 L of 0.200
M Na2SO4 solution.
BaCl2(aq) + Na2SO4(aq)  2 NaCl(aq) + BaSO4(s)
14. A mass of 98g of sulfuric acid (H2SO4) is dissolved in water to prepare a .50M solution.
What is the volume of the solution, in liters?