45: For each of the following pairs of gas properties, describe the relationship between the properties, describe a simple system that could be used to demonstrate the relationship, and explain the reason for the relationship:
(a) volume and pressure when number of gas particles and temperature are constant, (b) pressure and temperature when volume and the number of gas particles are constant, (c) volume and temperature when pressure and the number of gas particles are constant, (d) the number of gas particles and pressure when volume and temperature are constant, and (e) the number of gas particles and volume when pressure and temperature are constant.
56: Ethylene oxide is produced from the reaction of ethylene and oxygen at
270-290 °C and 8-20 atm. In order to prevent potentially dangerous pressure buildups, the container in which this reaction takes place has a safety valve set to release gas when the pressure reaches 25 atm. If a 15-m3 reaction vessel contains 7.8 × 103 moles of gas, at what temperature will the pressure reach 25 atm? (There are 103 L per m3.)
84: The hydrogen gas used to make ammonia can be made from small hydrocarbons such as methane in the so-called steam-reforming process, run at high temperature and pressure.
- If 3.2 atm of methane at 21 °C are introduced into a container, to what temperature must the gas be heated to increase the pressure to 12 atm?
- If 4.0 × 103 L of methane gas at 21 °C is heated and allowed to expand at a constant pressure, what will the volume become in m3 when the temperature reaches 815 °C?
- What volume of methane gas at 21 °C and 1.1 atm must be compressed to yield 1.5 × 104 L of methane gas at 12 atm and 815 °C?
- The hydrogen gas to make ammonia, hydrogen chloride gas, and methanol can be obtained from small hydrocarbons such as methane or propane through the steam-reforming process, conducted at 41 atm and 760-980 ̊C. If 2.7 x 107L of C3H3 (g) at 810 ̊C and 8.0 atm react in the first step of the process, shown below, what is the maximum volume in liters of CO(g) at STP that can form?
C3H8 + 3H2O→ 3CO + 7H2
3CO + 3H2O→ 3CO2 + 3H2
103: The atmosphere of Venus contains carbon dioxide and nitrogen gases. At the planet’s surface, the temperature is about 730 K, the total atmospheric pressure is 98 atm, and the partial pressure of carbon dioxide is 94 atm. If scientists wanted to collect 10.0 moles of gas from the surface of Venus, what volume of gas should they collect?
41: Acetone, CH3COCH3, is a laboratory solvent that is also commonly used as a
nail polish remover.
- Describe the submicroscopic events taking place at the surface of liquid
acetone when it evaporates.
- Do all of the acetone molecules moving away from the surface of the liquid
escape? If not, why not? What three criteria must be met for a molecule to
escape from the surface of the liquid and move into the gas phase?
- If you spill some nail polish remover on your hand, the spot will soon feel
- If you spill some acetone on a lab bench, it evaporates much faster than the
same amount of acetone in a test tube. Why?
- If you spill acetone on a hot plate in the laboratory, it evaporates much
more quickly than the same amount of acetone spilled on the cooler lab
50: Butane is a gas at room temperature and pressure, but the butane found in some
cigarette lighters is a liquid. How can this be?
55: Classify each of the following bonds as nonpolar covalent, polar covalent, or
ionic. If a bond is polar covalent, identify the atom that has the partial negative
charge and the atom that has the partial positive charge. If a bond is ionic,
identify the ion that has the negative charge and the ion that has the positive
- N−O d. H−I g. Se−I j. F−P
- Al−Cl e. Br−Cl h. N−Sr
- Cl−N f. Cl−S i. O−F
37: Would the following combinations be expected to be soluble or insoluble?
- polar solute and nonpolar solvent
- nonpolar solute and nonpolar solvent
- ionic solute and hexane
- molecular solute with small molecules and water
- hydrocarbon solute and hexane
41: Predict whether each of the following is soluble in water or not.
- potassium hydrogen sulfate, KHSO4 (used in wine making)
- the polar molecular compound propylene glycol, CH3CH(OH)CH2OH (used in some antifreezes)
- benzene, C6H6 (use to produce many organic compounds)
56: You throw a backyard party that resembles your idea of a big Texas barbecue. The guests get more food than they could possibly eat, including a big juicy steak in the center of each plate. Describe how soap or detergent can help you clean the greasy plates you’re left with when your guests go home, referring to the interactions between particles and the corresponding changes that take place on the submicroscopic level.
62: Some of the minerals found in rocks dissolve in water as it flows over the rocks. Would these minerals dissolve more quickly
- at the bottom of a waterfall or in a still pond? Why?
- in a cold mountain stream or in the warmer water downstream? Why?
- over large rocks or over sand composed of the same material? Why?
64: Solutions are called dilute when the concentration of the solute in solution is relatively low and concentrated when the concentration is relatively high. Can a solution be both dilute and saturated? Explain your answer.
68: You visit a dude ranch located in a beautiful mountain valley at an altitude of 6000 feet. The day you arrive, you decide to take your usual evening run. On this evening, however, you don’t run as far as usual, because you feel winded and tired much sooner than at home by the beach. Why does this happen?