4 chem questions.

Flask B: N2 at 250 ton and 0°C
Flask C: H, at 100 torr and 0°C
a. In which flask will the molecules have the greatest average kinetic energy?
Answer
b. In which flask will the molecules have the greatest average velocity?
Answer +
118. Consider separate 1.0-L gaseous samples of H., Xe, Cly, and O, all at STP.
a. Rank the gases in order of increasing average kinetic energy.
b. Rank the gases in order of increasing average velocity.
c. How can separate 1.0-L samples of O, and H, each have the same average velocity?
119. The effusion rate of an unknown gas is measured and found to be 31.50 mL/min. Under
identical experimental conditions, the effusion rate of 0,(9) is found to be 30.50 mL/min. If
the choices for the unknown gas are CH, CONO, CO2, and NO,, what is the identity of the
th
gas?
Answer
120. The rate of effusion of a particular gas was measured and found to be 24.0 mL/min. Under
the same conditions, the rate of effusion of pure methane (CH) gas is 47.8 mL/min. What
is the molar mass of the unknown gas?
121. One way of separating oxygen isotopes is by gaseous diffusion of carbon monoxide. The
gaseous diffusion process behaves like an effusion process. Calculate the relative rates of
effusion of 12C160, 1217, and 12C180. Name some advantages and disadvantages of
separating oxygen isotopes by gaseous diffusion of carbon dioxide instead of carbon
monoxide.
Answer +
122. It took 4.5 minutes for 1.0 L helium to effuse through a porous barrier. How long will it take
for 1.0 L Cl, gas to effuse under identical conditions?
123. Calculate the pressure exerted by 0.5000 mole of N, in a 1.0000-L container at 25.0°C
a. using the ideal gas law.
Answer
b. using the van der Waals equation.
Answer
c. Compare the results.
Answer +
124. Calculate the pressure exerted by 0.5000 mole of N, in a 10.000-L container at 25.0°C
a. using the ideal gas law.
Answer
b. Calculate the temperature of the air required for the hot air balloon to provide the
same lift as the helium balloon at 1.00 atm and 25°C. Assume atmospheric conditions
are 1.00 atm and 25°C.
Answer
166. We state that the ideal gas law tends to hold best at low pressures and high temperatures.
Show how the van der Waals equation simplifies to the ideal gas law under these
conditions.
167. You are given an unknown gaseous binary compound (that is, a compound consisting of
two different elements). When 10.0 g of the compound is burned in excess oxygen, 16.3 g of
water is produced. The compound has a density 1.38 times that of oxygen gas at the same
conditions of temperature and pressure. Give a possible identity for the unknown
compound.
Answer
168. Nitrogen gas (N2) reacts with hydrogen gas (H.) to form ammonia gas (NH). You have
nitrogen and hydrogen gases in a 15.0-L container fitted with a movable piston (the piston
allows the container volume to change so as to keep the pressure constant inside the
container). Initially the partial pressure of each reactant gas is 1.00 atm. Assume the
temperature is constant and that the reaction goes to completion.
a. Calculate the partial pressure of ammonia in the container after the reaction has
reached completion.
b. Calculate the volume of the container after the reaction has reached completion.
169. Consider a classroom containing ten evenly spaced rows of students. If a student in towi
releases laughing gas (N2O) and a student in tow 10 simultaneously releases a lachrymator
(a gas that causes tears) with molar mass of 176 g/mol, in which tow do the students first
laugh and cry at the same time?
Answer