Question 1

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 TA and TB in containers A and B, respectively, is

Accepted Answer

A) TA = TB. 
B) TA = 2TB. 
C) TA = $\frac { 1 } { 2 }$ TB. 
D) TA = $\frac { 1 } { \sqrt { 2 } }$ TB. 
E) TA = $\frac { 1 } { 4 }$ TB.

Question 2

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?

Accepted Answer

A) 129 kPa 
B) 483 kPa 
C) 507 kPa 
D) 517 kPa 
E) 532 kPa

Question 3

A 360-g metal container, insulated on the outside, holds 180.0 g of water in thermal equilibrium at 22.0°C. A 24.0-g ice cube, at the melting point, is dropped into the water, and when thermal equilibrium is reached the temperature is 15.0°C. Assume there is no heat exchange with the surroundings. For water, the specific heat capacity is 4190 J/kg ∙ K and the heat of fusion is 3.34 × 105 J/kg. What is the specific heat capacity of the metal of the container?

Accepted Answer

A) 1700 J/kg ∙ K 
B) 970 J/kg ∙ K 
C) 2300 J/kg ∙ K 
D) 2800 J/kg ∙ K 
E) 3300 J/kg ∙ K

Question 4

A sample of ideal monatomic gas is cooled by 50.0 C° at constant volume by removing 831 J of energy from it. How many moles of gas are in the sample? (R = 8.31 J/mol ∙ K)

Accepted Answer

A) 2.50 mol 
B) 1.50 mol 
C) 1.33 mol 
D) 1.00 mol

Question 5

An aluminum rod 17.400 cm long at 20°C is heated to 100°C. What is its new length? Aluminum has a linear expansion coefficient of 25 × 10-6 K-1.

Accepted Answer

A) 17.435 cm 
B) 17.365 cm 
C) 0.348 cm 
D) 0.0348 cm

Question 6

A solid cylindrical bar conducts heat at a rate of 25 W from a hot to a cold reservoir under steady state conditions. If both the length and the diameter of this bar are doubled, the rate at which it will conduct heat between these reservoirs will be

Accepted Answer

A) 200 W 
B) 100 W 
C) 50 W 
D) 25 W 
E) 12.5 W

Question 7

An ideal gas has a pressure of 2.5 atm, a volume of 1.0 L at a temperature of 30°C. How many molecules are there in this gas? (R = 8.31 J/mol ∙ K,1.00 atm = 101 kPa, NA = 6.022 × 1023)

Accepted Answer

A) 6.1 × 1023 
B) 6.0 × 1022 
C) 2.4 × 1022 
D) 2.3 × 1023

Question 8

A 24.0-L tank contains ideal helium gas at 27°C and a pressure of 22.0 atm. How many moles of gas are in the tank? (R = 8.31 J/mol ∙ K, 1 atm = 101 kPa)

Accepted Answer

A) 238 mol 
B) 138 mol 
C) 17.5 mol 
D) 21.4 mol 
E) 76.0 mol

Question 9

Two processes are shown on the pV diagram in the figure. One of them is an adiabat and the other one is an isotherm. Which process is the isotherm?

Accepted Answer

A) process A 
B) process B 
C) The processes shown are neither isotherms nor adiabats. 
D) It is not possible to tell without knowing if the gas is monatomic or diatomic.

Question 10

Originally 2.00 mol of gas are at STP. If the temperature changes to 47.0°C and the pressure decreases to half of what it was, how many liters do the two moles now occupy? (1 atm = 101 kPa, R = 8.31 J/mol ? K)

Accepted Answer

The answer of Originally 2.00 mol of gas are at...

Question 11

A gas expands from an initial volume of 30.0 L to a final volume of 65.0 L at a constant pressure of 110 kPa. How much work is done by the gas during this expansion?

Accepted Answer

A) 3.85 kJ 
B) 10.4 kJ 
C) 3850 kJ 
D) 10.4 MJ 
E) 3.85 MJ

Question 12

A hole in a brass plate has a diameter of 1.200 cm at 20°C. What is the diameter of the hole when the plate is heated to 220°C? The coefficient of linear thermal expansion for brass is 19 × 10-6 K-1.

Accepted Answer

A) 1.205 cm 
B) 1.195 cm 
C) 1.200 cm 
D) 1.210 cm

Question 13

A jar holds 2.0 L of ideal nitrogen gas, N₂, at STP. The atomic mass of nitrogen is 14.0 g/mol, the ideal gas constant is R = 8.31 J/mol ? K, Avogadro's number is N_A = 6.022 × 10²³ molecules/mol, and 1.00 atm = 101 kPa. (a)How many moles of nitrogen are in the jar? (b)How many nitrogen molecules are in the jar? (c)What is the mass of the nitrogen in the jar?

Accepted Answer

The answer of A jar holds 2.0 L of ideal...

Question 14

If the absolute temperature of an object is tripled, the thermal power radiated by this object (assuming that its emissivity and size are not affected by the temperature change)will

Accepted Answer

A) increase by a factor of 3. 
B) increase by a factor of 9. 
C) increase by a factor of 18. 
D) increase by a factor of 27. 
E) increase by a factor of 81.

Question 15

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?

Accepted Answer

A) initial temperature 
B) specific heat 
C) density 
D) coefficient of linear expansion 
E) thermal conductivity

Question 16

Oxygen molecules are 16 times more massive than hydrogen molecules. At a given temperature, the average molecular kinetic energy of oxygen molecules, compared to that of hydrogen molecules,

Accepted Answer

A) is greater. 
B) is less. 
C) is the same. 
D) cannot be determined without knowing the pressure and volume.

Question 17

A 40.0-g block of ice at -15.00°C is dropped into a calorimeter (of negligible heat capacity)containing water at 15.00°C. When equilibrium is reached, the final temperature is 8.00°C. How much water did the calorimeter contain initially? The specific heat of ice is 2090 J/kg ∙ K, that of water is 4186 J/kg ∙ K, and the latent heat of fusion of water is 33.5 × 104 J/kg.

Accepted Answer

A) 302 g 
B) 345 g 
C) 405 g 
D) 546 g 
E) 634 g

Question 18

A sphere of surface area 1.25 m2 and emissivity 1.0 is at a temperature of 100°C. At what rate does it radiate heat into empty space? (σ = 5.67 × 10-8 W/m2 ∙ K4)

Accepted Answer

A) 7.1 W 
B) 0.71 mW 
C) 1.4 kW 
D) 9.9 mW 
E) 3.7 W

Question 19

A 0.600-kg piece of metal X is heated to 100°C and placed in an aluminum can of mass 0.200-kg which contains 0.500 kg of water initially at 17.3°C. The final equilibrium temperature of the mixture is 20.2°C, what is the specific heat of metal X? The specific heats of water and aluminum are 4186 J/kg ∙ K (water)and 910 J/kg ∙ K (aluminum).

Accepted Answer

A) 140 J/kg ∙ K 
B) 270 J/kg ∙ K 
C) 450 J/kg ∙ K 
D) 900 J/kg ∙ K

Question 20

The coefficient of linear expansion of copper is 17 × 10-6 K-1. A sheet of copper has a round hole with a radius of 3.0 m cut out of it. If the sheet is heated and undergoes a change in temperature of 80 K, what is the change in the radius of the hole?

Accepted Answer

A) It decreases by 4.1 mm. 
B) It increases by 4.1 mm. 
C) It decreases by 8.2 mm. 
D) It increases by 8.2 mm. 
E) It does not change.

Exam 12: Thermal Properties of Matter

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 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?

A sample of ideal monatomic gas is cooled by 50.0 C° at constant volume by removing 831 J of energy from it. How many moles of gas are in the sample? (R = 8.31 J/mol ∙ K)

An aluminum rod 17.400 cm long at 20°C is heated to 100°C. What is its new length? Aluminum has a linear expansion coefficient of 25 × 10^-6 K^-1.

A solid cylindrical bar conducts heat at a rate of 25 W from a hot to a cold reservoir under steady state conditions. If both the length and the diameter of this bar are doubled, the rate at which it will conduct heat between these reservoirs will be

An ideal gas has a pressure of 2.5 atm, a volume of 1.0 L at a temperature of 30°C. How many molecules are there in this gas? (R = 8.31 J/mol ∙ K,1.00 atm = 101 kPa, N_A = 6.022 × 10²³)

A 24.0-L tank contains ideal helium gas at 27°C and a pressure of 22.0 atm. How many moles of gas are in the tank? (R = 8.31 J/mol ∙ K, 1 atm = 101 kPa)

Two processes are shown on the pV diagram in the figure. One of them is an adiabat and the other one is an isotherm. Which process is the isotherm?

Originally 2.00 mol of gas are at STP. If the temperature changes to 47.0°C and the pressure decreases to half of what it was, how many liters do the two moles now occupy? (1 atm = 101 kPa, R = 8.31 J/mol ? K)

A gas expands from an initial volume of 30.0 L to a final volume of 65.0 L at a constant pressure of 110 kPa. How much work is done by the gas during this expansion?

A hole in a brass plate has a diameter of 1.200 cm at 20°C. What is the diameter of the hole when the plate is heated to 220°C? The coefficient of linear thermal expansion for brass is 19 × 10^-6 K^-1.

If the absolute temperature of an object is tripled, the thermal power radiated by this object (assuming that its emissivity and size are not affected by the temperature change) will

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?

Oxygen molecules are 16 times more massive than hydrogen molecules. At a given temperature, the average molecular kinetic energy of oxygen molecules, compared to that of hydrogen molecules,

A sphere of surface area 1.25 m² and emissivity 1.0 is at a temperature of 100°C. At what rate does it radiate heat into empty space? (σ = 5.67 × 10^-8 W/m² ∙ K⁴)

The coefficient of linear expansion of copper is 17 × 10^-6 K^-1. A sheet of copper has a round hole with a radius of 3.0 m cut out of it. If the sheet is heated and undergoes a change in temperature of 80 K, what is the change in the radius of the hole?