Problem Set Chapter 5
Basic
1. What is the pressure in mm Hg exerted by 2.40 grams of O2 if the volume is 1400 mL
and the temperature is 27 oC?
2. What must the final temperature be (in oC) if 600 mL of hydrogen at 125 oC is to be
cooled so that its volume is 275 mL with no pressure change?
3. A steel cylinder holds 1.50 grams of ethanol, C2H5OH. What is the pressure of the
ethanol vapor if the cylinder has a volume of 251 cm3 and the temperature is 250 oC?
(Assume all the ethanol is in the vapor phase at this temperature.)
4. What is the total pressure in atmospheres of a gas mixture that contains1.0 g H2 and
8.0 g of Ar in a 3.0 L container at 27 oC? What are the partial pressures of the two
gases?
Involved
1. Boron hydride reacts with oxygen in the following way
2B4H10(g) + 11O2(g) 4B2O3(s) + 10H2O(g)
If a 0.50 gram sample of boron hydride reacts with excess oxygen, what will be the
pressure of gaseous water in a 4.25 liter flask at 30.0 oC?
2. An adult exhales about 15 times per minute, with each exhalation having a volume of
500 . mL. Assuming the inhaled air has no water, but the exhaled air is water
vapor at 37.0 oC, what mass of water is lost from the body in one day? The vapor
pressure of water at 37.0 oC is 47.1 Torr. Use the molar mass of water.
3. Explosions occur when a substance decomposes rapidly with the production of a large
volume of gases. When detonated, TNT decomposes according to the equation:
2C7H5(NO2)3(s) 12CO(g) + 2C(s) + 5H2(g) + 3N2(g)
What is the total volume of gases produced from 1.00 kg of TNT if collected at
25.00 oC and 1.00 atm?
4. Benzene is burned according to the following reaction:
2C6H6(l) + 15O2(g) 12CO2(g) + 6H2O(l)
