Tiger Invitational — Thermodynamics

First to relate physical work to heat production in the body

The thermodynamic phase rule is credited to

Related heat to electrical current Q = U I dt

Discovered that work was proportional to heat transfer from boiler to condenser.

Stated that heat transfer is proportional to differences in temperature/

Described the kinetic theory of matter

The temperature in your classroom is closest to

Consider two equal-volume flasks of gas at the same temperature and pressure. One gas, oxygen, has a molecular mass of 32. The other gas, nitrogen, has a molecular mass of 28. What is the ratio of the number of oxygen molecules to the number of nitrogen molecules in these flasks?

The absolute temperature of an ideal gas is directly proportional to which of the following quantities?

Express -40°C in °F.

A car starts out when the air temperature is 288 K and the absolute (total) air pressure in the tires is 500 kPa. After driving a while, the temperature of the air in the tires increases to 298 K. What is the pressure in the tires at that point, assuming their volume does not change?

Which one of the following quantities is the smallest unit of heat energy?

The figure shows a graph of the temperature of a pure substance as a function of time as heat is added to it at a constant rate in a closed container. If L_F is the latent heat of fusion of this substance and L_V is its latent heat of vaporization, what is the value of the ratio L_V/L_F?

On a cold day, a piece of metal feels much colder to the touch than a piece of wood. This is due to the difference in which one of the following physical properties of these materials?

When a gas expands adiabatically,

The process in which heat flows by the mass movement of molecules from one place to another is known as

In a given reversible process, the temperature of an ideal gas is kept constant as the gas is compressed to a smaller volume. Which one of the following statements about the gas is correct?

The process shown on the pV diagram in the figure is an

A 10-L flask and a 1-L flask each contain two moles of ideal diatomic gas (but not the same gas) at 25°C. Which of the following statements about these gases must be true? (There could be more than one correct choice.)

A cyclic process is carried out on an ideal gas such that it returns to its initial state at the end of a cycle, as shown in the pV diagram in the figure. If the process is carried out in a clockwise sense around the enclosed area, as shown on the figure, then the change of internal energy over the full cycle

How much heat is required to raise the temperature of a 225-g lead ball from 15.0°C to 25.0°C? The specific heat of lead is 128 J/kg ∙ K.

An aluminum electric tea kettle with a mass of 500 g is heated with a 500-W heating coil. How long will it take to heat up 1.0 kg of water from 18°C to 98°C in the tea kettle? The specific heat of aluminum is 900 J/kg ∙ K and that of water is 4186 J/kg ∙ K.

It is necessary to determine the specific heat of an unknown object. The mass of the object is 201.0 g. It is determined experimentally that it takes 15.0 J to raise the temperature 10.0°C. What is the specific heat of the object?

A glass beaker of unknown mass contains 74.0 ml of water. The system absorbs 2000.0 cal of heat and the temperature rises 20.0°C as a result. What is the mass of the beaker? The specific heat of glass is 0.18 cal/g ∙ °C, and that of water is 1.0 cal/g ∙ C°.

In a flask, 114.0 g of water is heated using 67.0 W of power, with perfect efficiency. How long will it take to raise the temperature of the water from 15°C to 25°C? The specific heat of water is 4186 J/kg ∙ K.

How much heat must be removed from 456 g of water at 25.0°C to change it into ice at -10.0°C? The specific heat of ice is 2090 J/kg ∙ K, the latent heat of fusion of water is 33.5 × 10⁴ J/kg, and the specific heat of water is 4186 J/kg ∙ K.

Heat is added to a 3.0 kg piece of ice at a rate of 636.0 kW. How long will it take for the ice at 0.0°C to melt? For water L_F = 334,000 J/kg and L_V = 2.246 × 10⁶ J/kg.

An ideal gas undergoes the process a → b → c → a shown in the pV diagram. In this figure, P_a = P_c = 3.60 × 10⁵ Pa, V_b = V_c = 68.00 L, V_a = 35 L, and P_b = 5.60 × 10⁵ Pa. How much work is done by the system in this process?

An ideal gas undergoes an adiabatic process while doing 25 J of work. What is the change in the internal (thermal) energy of the gas?

An athlete doing push-ups performs 650 kJ of work and loses 425 kJ of heat. What is the change in the internal (thermal) energy of the athlete?

The second law of thermodynamics leads us to conclude that

An important feature of the Carnot cycle is that

An ideal gas undergoes an isothermal expansion. During this process, its entropy

When water at 0°C freezes, the entropy of the water

The figure shows a pV diagram for a cycle of a heat engine for which Q_H = 59 J. What is the thermal efficiency of the engine?

An ideal Carnot heat engine operates between 285 K and 460 K. What is its efficiency?

A heat engine having the maximum possible efficiency has an efficiency of 25% when operating between two heat reservoirs. If the temperature of the cold reservoir is 300 K, what is the temperature of the hot reservoir?

An ideal Carnot engine has an efficiency of 83.0% and performs 4500 J of work every cycle. How much energy is discharged to the lower temperature reservoir every cycle?

If you wanted to know how much the temperature of a particular piece of material would rise when a known amount of heat was added to it, which of the following quantities would be most helpful to know?

A thermally isolated system is made up of a hot piece of aluminum and a cold piece of copper, with the aluminum and the copper in thermal contact. The specific heat capacity of aluminum is more than double that of copper. Which object experiences the greater temperature change during the time the system takes to reach thermal equilibrium?

Object 1 has three times the specific heat capacity and four times the mass of Object 2. The two objects are heated from the same initial temperature, T₀, to the same final temperature T_f. During this process, if Object 1 absorbs heat Q, the amount of heat absorbed by Object 2 will be

A temperature change of 20 C° corresponds to a Fahrenheit temperature change of

When a gas expands adiabatically,

If the efficiency of a Carnot engine were to be 100%, the heat sink would have to be

The temperature of an ideal gas in a sealed rigid 0.20-m³ container is reduced from 360 K to 270 K, and the final pressure of the gas is 40 kPa. How much work is done by the gas during this process? (R = 8.31 J/mol·K)