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문제 69
An 8.5-g ice cube is placed into 255 g of water. Calculate the temperature change in the water upon the complete melting of the ice. Assume that all of the energy required to melt the ice comes from the water.
문제 70
How much ice (in grams) would have to melt to lower the temperature of 352 mL of water from 25 °C to 5 °C? (Assume the density of water is 1.0 g/mL.)
문제 73
Consider the phase diagram shown here. Identify the states present at points a through g.
- Consider the phase diagram for iodine shown here. a. What is the normal boiling point for iodine? b. What is the melting point for iodine at 1 atm? c. What state is present at room temperature and normal atmospheric pressure? d. What state is present at 186 °C and 1.0 atm?
문제 74
문제 75
Nitrogen has a normal boiling point of 77.3 K and a melting point (at 1 atm) of 63.1 K. Its critical temperature is 126.2 K and its critical pressure is 2.55×104 torr. It has a triple point at 63.1 K and 94.0 torr. Sketch the phase diagram for nitrogen. Does nitrogen have a stable liquid state at 1 atm?
문제 76
Argon has a normal boiling point of 87.2 K and a melting point (at 1 atm) of 84.1 K. Its critical temperature is 150.8 K and its critical pressure is 48.3 atm. It has a triple point at 83.7 K and 0.68 atm. Sketch the phase diagram for argon. Which has the greater density, solid argon or liquid argon?
문제 77a
The phase diagram for sulfur is shown here. The rhombic and monoclinic states are two solid states with different structures. a. Below what pressure does solid sulfur sublime?
문제 77b
The phase diagram for sulfur is shown here. The rhombic and monoclinic states are two solid states with different structures. b. Which of the two solid states of sulfur is more dense?
- Water has a high boiling point given its relatively low molar mass. Why?
문제 79
문제 80
Water is a good solvent for many substances. What is the molecular basis for this property, and why is it significant?
- Explain the role of water in moderating Earth's climate.
문제 81
- How is the density of solid water compared to that of liquid water atypical among substances, and why is this significant?
문제 82
문제 83
Explain the observed trend in the melting points of the hydrogen halides.
HI -50.8 °C
HBr -88.5 °C
HCl -114.8 °C
HF -83.1 °C
문제 84
Explain the observed trend in the boiling points of these compounds.
H2Te -2 °C
H2Se -41.5 °C
H2S -60.7 °C
H2O 100 °C
문제 85
The vapor pressure of water at 25 °C is 23.76 torr. If 1.25 g of water is enclosed in a 1.5-L container, will any liquid be present? If so, what mass of liquid?
문제 86
The vapor pressure of CCl3F at 300 K is 856 torr. If 11.5 g of CCl3F is enclosed in a 1.0-L container, will any liquid be present? If so, what mass of liquid?
- Four ice cubes at exactly 0 °C with a total mass of 53.5 g are combined with 115 g of water at 75 °C in an insulated container. If no heat is lost to the surroundings, what is the final temperature of the mixture?
문제 89
문제 90
A sample of steam with a mass of 0.552 g and at a temperature of 100 °C condenses into an insulated container holding 4.25 g of water at 5.0 °C. Assuming that no heat is lost to the surroundings, what is the final temperature of the mixture?
문제 93
Air conditioners not only cool air, but dry it as well. A room in a home measures 6.0 m × 10.0 m × 2.2 m. If the outdoor temperature is 30 °C and the partial pressure of water in the air is 85% of the vapor pressure of water at this temperature, what mass of water must be removed from the air each time the volume of air in the room is cycled through the air conditioner? (Assume that all of the water must be removed from the air.) The vapor pressure for water at 30 °C is 31.8 torr.
문제 94
A sealed flask contains 0.55 g of water at 28 °C. The vapor pressure of water at this temperature is 28.35 mmHg. What is the minimum volume of the flask in order that no liquid water be present in the flask?
문제 95a
Based on the phase diagram of CO2 shown in Figure 11.39(b), describe the state changes that occur when the temperature of CO2 is increased from 190 K to 350 K at a constant pressure of (a) 1 atm