Exam 17: Phases and Phase Changes

Two containers of equal volume each hold samples of the same ideal gas. Container A has twice as many molecules as container B. If the gas pressure is the same in the two containers, the correct statement regarding the absolute temperatures T_A and T_B in containers A and B, respectively, is

A laboratory vacuum pump can reduce the pressure to 1.0 × 10^-7 Pa. If the volume of the chamber is 0.500 m³ and the temperature is 27°C, how many molecules are left inside the chamber?

The melting point of aluminum is 660°C, the latent heat of fusion is 4.00 × 10⁵ J/kg, and its specific heat is 900 J/(kg K). 300 kJ of heat are added to 442 g of aluminum at 100°C, what is the final state of the system?

The internal energy of an ideal gas depends on

A vertical cylindrical cylinder, closed at the bottom end, contains 0.0100 moles of gas. It is fitted at the top with a piston, which can move freely. The mass of the piston is 14.0 kg and the initial height of the piston above the bottom of the cylinder is 25 cm. What is the temperature of the gas?

What is the rms speed of a helium atom: (a) at 5. K? (b) at -196.° C (the boiling point of N₂)? (c) at 100.° C?

What is the internal energy in 2.7 moles of hydrogen at 300 K? As an approximation, treat the hydrogen gas as if it was monatomic.

What is the temperature of 3.0 moles of gas at a pressure of 250 kPa held in a volume of 15 L?

When comparing two gases at the same temperature, the gas with a higher molecular weight has more internal energy per mole.

An automobile tire has a volume of 0.0185 m³. If the pressure in the tire is 500 kPa and the temperature is 298 K, how many molecules are there inside the tire?

A 40.0-g block of ice at -15.0°C is dropped into a calorimeter (of negligible heat capacity) containing water at 15.0°C. When equilibrium is reached, the final temperature is 8.0°C. How much water did the calorimeter contain initially? The specific heat of ice is 2090 J/(kg K) and the latent heat of fusion of water is 33.5 × 10⁴ J/kg.

The heat required to change a substance from the liquid to the vapor state is referred to as the

According to kinetic theory, the temperature of a gas is determined by the average kinetic energy of its molecules. What would happen if the gas were in a container that was moving with a high velocity?

An 920-g piece of iron at 100°C is dropped into a calorimeter of negligible heat capacity containing 50 g of ice at 0°C and 92 g of water, also at 0°C. What is the final temperature of the system? The specific heat of iron is 448 J/(kg K) and the latent heat of fusion of water is 33)5 × 10⁴ J/kg.

In kinetic theory, a gas is modeled as being made up of a large number of molecules which bounce from the walls of the container.

La Paz, Bolivia, is at an altitude of 3,650 meters above sea level. In La Paz, water will boil

The point in the phase diagram where the fusion curve, the vapor pressure curve, and the sublimation curve join is called the

When comparing two gases at the same temperature, the molecules of the gas with the smaller molecular weight have the higher rms speed.

In a city high in the mountains, such as Denver, CO, water boils

When both the pressure and the absolute temperature of an ideal gas are increased each by a factor of two, the volume occupied by the gas will