Studied by 6 people
Heat
The transfer of thermal energy. Heat is not a substance, and does not flow. It can only be transferred
Thermal energy
The kinetic energy of the particles in a substance due to their random motion
Temperature
A measure of the average kinetic energy of the atoms or molecules of a substance
Kinetic molecular theory
All matter is composed of moving particles. Particles in hot materials move faster than particles in cooler materials, so they have more kinetic energy
________________ is generated by particle movement in an object or system and is linked to its temperature. Higher temperatures mean more thermal energy. It can be transferred between objects through conduction, convection, or radiation.
Thermal energy
First law of thermodynamics
The change in the energy of a system is the sum of the work and heat exchanged between a system and its surroundings
ΔE = W+ Q
When is the work negative?
When the system does work on its surroundings, it loses energy, so W is negative
When is the heat transferred negative?
If heat is transferred out of the system, energy is lost, so Q is negative
Second law of thermodynamics
Thermal energy is always transferred from an object at a higher temperature to an object at a lower temperature. The transfer will continue until thermal equilibrium is reached.
Thermal equilibrium
Thermal equilibrium means that both objects are at the same temperature.
Who developed the Celsius Scale?
Anders Celsius
Who developed the Kelvin Scale?
Lord Kelvin
How to convert Celsius degrees to Kelvin degrees?
T = Tc + 273.15
How to convert Kelvin degrees to Celsius degrees?
Tc = T - 273.15
Specific heat capacity
The amount of energy that must be added to raise the temperature of 1.0kg of a substance by 1.0K.
Phase change
Refers to the change of state of a material
What happens when a material reaches a temperature at which it changes state?
The addition of heat energy will not change the material’s temperature
Latent heat
The amount of heat required to change phase
When will be greater the amount of heat required?
A. Changing a mterial’s phase
B. Increasing the material’s temperature by one degree
A. A larger amount of heat is required to change a mterial’s phase than the heat required to increase the material’s temperature by one degree (Breaking the bonds between molecules requires much more energy).
Latent heat of fusion
Heat required to change one kilogram of the material from a solid to a liquid
Latent heat of vaporization
Heat required to change one kilogram to the material from a liquid to a gas
How much heat energy is required to heat 2.0 kg of copper from 30.0°C to 80.0°C?
Copper / Specific heat capacity: 3.8 X 10² (J/(Kg.°C))
38 Kj
If 3.0 × 10^4 J of heat energy is transferred to a 1.0kg block of aluminum initially at 10°C, what will the final temperature be?
Aluminum // Specific heat capacity: 9.2 X 10²(J/(Kg.°C))
43°C
How much energy is required to change 2.0kg of ice at 0.0°C to water at 0.0°C?
Water // Lf: 3.4 X 10^5 (J/Kg)
Water // Lv: 2.3 X 10^6 (J/Kg)
Water // Specific heat capacity 4.18 X 10³ (J/(Kg.°C))
6.8 X 10^5 J
How much heat does a refrigerator have to remove from 1.5 kg of water at 20.0°C to make ice at -10.0°C? Answer in kJ
Water // Lf: 3.4 X 10^5 (J/Kg)
Water // Lv: 2.3 X 10^6 (J/Kg)
Water // Specific heat capacity 4.18 X 10³ (J/(Kg.°C))
-666.9 kJ
A 5.0 kg Aluminum statue is cooled from 2700|C to room temperature. Calculate the thermal energy released.
Aluminum // Specific heat capacity: 9.2 X 10² (J/(Kg.°C))
Aluminum // Specific latent heat of fusion: 6.6 X 10^5 (J/Kg)
Aluminum // Specific latent heat of vaporization: 4.0 X 10^5 (J/Kg)
16 MJ
How much thermal energy is required to heat 5.0 kg of water at a temperature of 45°C to steam at a temperature of 125°C if it is at a constant pressure?
1.3 × 10^7 J
How much thermal energy is required to turn 12 kg of ice at a temperature of -25°C into water with a temperature of 75°C?
8.4 X 10^6 J
Lead has a melting point of 327°C. How much thermal energy is required to run a 2.0 kg lump of lead into liquid lead if the temperature changes from room temperature (20°C) to a liquid at a temperature of 327°C?
1.3 X 10^5 J
How much thermal energy is required to change 0.50 kg of ice at a temperature of -25°C into steam at 120°C if there is constant pressure?
1.6 X 10^6
If 1.00 kg of ice was at a temperature of -40.0°C and 5.00X10^5 J of thermal energy was added then what is the final state and temperature of the H2O?
Liquid. 21°C
Rearrange Q = mcΔT to find the final temperature
T2 = T1 + (Q/mc)
Differentiate between temperature and thermal energy.
Temperature indicates the average kinetic energy of particles in a substance, reflecting its hotness or coldness.
Thermal energy involves the total internal energy, including both kinetic and potential energy, and its influenced by the amount of matter.
Describe how the kinetic molecular theory explains the changes of state in substances.
The kinetic molecular theory explains that as substances increase their thermal energy, the particles move faster, overcoming intermolecular forces and causing a transition from solid to liquid and then to gas.
Comversely, cooling reduces particle motion, leading to transitions from gas to liquid and to solid states.
Convert each temperature to kelvins.
(a) 32 °C
(b) 210 °C
(c) 95 °C
(a) 305 K
(b) 263 K
(c) 368 K
Convert each temperature to degrees Celsius.
(a) 200 K
(b) 373 K
(c) 298 K
(a) 73°C
(b) 100°C
(c) 25°C
How much thermal energy is required to raise the temperature of 2.0 kg of water by 10.0 °C?
Water // Lf: 3.4 X 10^5 (J/Kg)
Water // Lv: 2.3 X 10^6 (J/Kg)
Water // Specific heat capacity 4.18 X 10³ (J/(Kg.°C))
8.4 X 10^4 J
A glass window with a mass of 20.0 kg is heated to a temperature of 32.0 °C by the Sun. How much thermal energy is released by the window to the surroundings as it cools to 5.0 °C at night?
Glass specific heat capacity: 8.4 X 10²
4.5 X 10^5 J
An aluminum block absorbs 1.0X10V^4 J of energy from the Sun when its temperature increases by 5.0 °C. What is the mass of the block?
Aluminum // Specific heat capacity: 9.2 X 10² (J/(Kg.°C))
Aluminum // Specific latent heat of fusion: 6.6 X 10^5 (J/Kg)
Aluminum // Specific latent heat of vaporization: 4.0 X 10^5 (J/Kg)
2.2 kg
What is specific heat capacity? What does it tell you?
Specific heat capacity is the amount of heat energy required to raise the temperature of 1,0 kg of a substance by 1 degree celsius. It shows a material’s ability to store heat.
Calculate the amount of thermal energy required to increase the temperature of 25.0 g of silver from 50.0 °C to 80.0 °C.
Silver specific heat capacity: 2.4 X 10²
1.8 X 10² J
Calcium has a specific heat capacity of 6.3 3 10² J/(kg.°C). Determine the final temperature of a 60.0 g sample of calcium if it starts at 10.0 °C and absorbs 302 J of thermal energy.
18°C
How much thermal energy is released when 2.0 L of liquid water freezes?
Water // Lf: 3.4 X 10^5 (J/Kg)
Water // Lv: 2.3 X 10^6 (J/Kg)
Water // Specific heat capacity 4.18 X 10³ (J/(Kg.°C))
6.8 X 10^5 J
How much thermal energy is absorbed when a 350 g bar of gold melts?
Gold Lf: 1.1 X 10^6 (J/Kg)
Gold Lv: 6.4 X 10^4 (J/Kg)
3.9 X 10^5 J
How much thermal energy is released when 500 g of steam at 100 °C condenses into liquid water and then cools to 50 °C?
Water // Lf: 3.4 X 10^5 (J/Kg)
Water // Lv: 2.3 X 10^6 (J/Kg)
Water // Specific heat capacity 4.18 X 10³ (J/(Kg.°C))
1.3 X 10^6 J
(a) Use Table 2 to graph a heating curve.
(b) Label the appropriate parts of the graph with the following: solid, liquid, gas, melting, evaporation.
(c) Determine the melting point and boiling point of the substance.
Time (min) | 0.5 | 1.0 | 1.5 | 2.0 | 2.5 | 3.0 | 3.5 | 4.0 | 4.5 | 5.0 | 5.5 | 6.0 | 6.5 | 7.0 | 7.5 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Temperature (°C) | 37 | 43 | 49 | 55 | 55 | 55 | 56 | 64 | 70 | 80 | 86 | 90 | 90 | 90 | 100 |
(c) melting point is 55 °c. Boiling point is 90 °C
Describe what would happen if you were to heat liquid water to a temperature of 110 °C.
When the temperature reach 100°C, it will start to vaporize, and its temperature will remain at 100°C until all the water become vapour. You can never increase the temperature to 110°C until you increase the pressure.
Explain the terms “latent heat of fusion” and “latent heat of vaporization.”
The "latent heat of fusion" refers to the amount of heat energy required to change a substance from a solid to a liquid state at its melting point, without changing its temperature. The "latent heat of vaporization" is the amount of heat energy needed to convert a substance from a liquid to a gas state at its boiling point, without changing its temperature. Both processes involve the absorption or release of energy without a change in temperature.
How much thermal energy is needed to change 100 g of ice at 220 °C into steam at 110 °C?
Water // Lf: 3.4 X 10^5 (J/Kg)
Water // Lv: 2.3 X 10^6 (J/Kg)
Water // Specific heat capacity 4.18 X 10³ (J/(Kg.°C))
Ice // Specific heat capacity 2.1 X 10³ (J/(Kg.°C))
3.2 X 10^5 J
While forming a 1.50 kg aluminum statue, a metal smith heats the aluminum to 2700 °C, pours it into a mould, and then cools it to a room temperature of 23.0 °C. Calculate the thermal energy released by the aluminum during the process.
Aluminum // Specific heat capacity: 9.2 X 10² (J/(Kg.°C))
Aluminum // Specific latent heat of fusion: 6.6 X 10^5 (J/Kg)
Aluminum // Specific latent heat of vaporization: 4.0 X 10^5 (J/Kg)
2.7 X 10^6 J
Sun-Young places a 2.0 kg block of aluminum that had been heated to 100.0 °C in 1.5 kg of ethyl alcohol with an initial temperature of 18.0 °C. What is the final temperature of the mixture?
Aluminum // Specific heat capacity: 9.2 X 10² (J/(Kg.°C))
Aluminum // Specific latent heat of fusion: 6.6 X 10^5 (J/Kg)
Aluminum // Specific latent heat of vaporization: 4.0 X 10^5 (J/Kg)
Ethyl alcohol// Specific heat capacity: 2.46 X 10³ (J/(Kg.°C))
Ethyl alcohol // Lf: 1.1 X 10^5 (J/Kg)
Ethyl alcohol // Lv: 8.6 X 10^5 (J/Kg)
45°C
A metal bar with a mass of 4.0 kg is placed in boiling water until its temperature stabilizes at 100.0 °C. The bar is then immersed in 500.0 mL of water with an initial temperature of 20.0 °C. The mixture reaches a temperature of 35.0 °C. What is the specific heat capacity of the metal bar?
Water // Lf: 3.4 X 10^5 (J/Kg)
Water // Lv: 2.3 X 10^6 (J/Kg)
Water // Specific heat capacity 4.18 X 10³ (J/(Kg.°C))
1.2 X 10² (J/(Kg.°C))
The total amount of kinetic energy and potential energy possessed by the particles of a substance is its
(a) heat
(b) temperature
(c) kelvins
(d) thermal energy
D
2273 °C is known as
(a) the freezing point
(b) absolute zero
(c) heat capacity
(d) specific latent heat
B
At 646 m above sea level, water boils at 97.9 °C. What
is this temperature in kelvins?
(a) 2175 K
(c) 212 K
(b) 0 K
(d) 371 K
D
The type of thermal energy transfer that can occur in solids, liquids, and gases is
(a) radiation
(b) conduction
(c) convection
(d) all of the above
B
The amount of energy that must be added to a substance to raise 1.0 kg of the substance by 1 °C is the substance’s
(a) temperature
(b) thermal energy
(c) specific heat capacity
(d) kinetic energy
C
The SI unit of energy is named after which scientist?
(a) Isaac Newton
(b) Lord Kelvin
(c) John Dalton
(d) James Joule
D
Find the amount of thermal energy lost when 300.0 g of aluminum cools from 120 °C to 55 °C.
Aluminum // Specific heat capacity: 9.2 X 10² (J/(Kg.°C))
Aluminum // Specific latent heat of fusion: 6.6 X 10^5 (J/Kg)
Aluminum // Specific latent heat of vaporization: 4.0 X 10^5 (J/Kg)
-1.8 X 10^4 J
A 50.0 g sample of lead starts at 22 °C and is heated until it absorbs 8.7 X 10² J of energy. Find the final temperature of the lead.
Lead // Specific heat capacity: 1.3 X 10² (J/(Kg.°C))
Lead Lf: 2.5 X 10^4 (J/Kg)
Lead Lv: 8.7 X10^5 (J/Kg)
160°C
A copper wire that has been heated to 520 °C for pliability is plunged into 350 mL of water at 18 °C. Th e final temperature of the copper and water bath is 31 °C. Find the mass of the copper wire. 67
Water // Lf: 3.4 X 10^5 (J/Kg)
Water // Lv: 2.3 X 10^6 (J/Kg)
Water // Specific heat capacity 4.18 X 10³ (J/(Kg.°C))
Copper // Specific heat capacity 3.8 X 10² (J/(Kg.°C))
0.10 kg
Note 
Flashcard (46)