90 Questions
Which of the following is true about the coexistence of vapor and liquid?
The coexistence of vapor and liquid is represented by the length of plateau DE.
What is the latent heat of vaporization for water?
2257 kJ/kg
What is the latent heat of fusion for water?
335 kJ/kg
What is the effective freezing time defined as?
The time required to reduce the temperature at the slowest cooling point from the ambient temperature to -15 oC.
What is freeze concentration?
The process of increasing the concentration of solutes in unfrozen material during freezing.
What is the total heat required to freeze 200kg of apples from 25 oC to -20 oC?
82112 kJ
What is the change in enthalpy given by?
ΔH = ΔU - pΔV + pΔV
What is the enthalpy change equal to for a process taking place at constant pressure?
Heat absorbed or evolved
What happens for the reverse process of vaporization?
Heat is evolved and the process is exothermic
What is enthalpy often equated with?
Heat content
According to the text, which method can be used to minimize heat loss to the surroundings in an experiment?
Insulating the calorimeter
According to the text, what is the relationship between the rate of heat loss from a sample and the rate of heat loss from a reference material in the method of cooling?
They are equal
According to the text, what is Newton's law of cooling?
Rate of heat loss from a body is directly proportional to the excess temperature of the body above that of its surroundings
According to the text, what is the relationship between the specific heat and the rate of heat loss in the method of cooling?
There is no relationship
According to the text, what is the purpose of using an electrical element in a calorimeter?
To eliminate heat loss from the liquid
According to the text, what is the equation for calculating the rate of heat loss in a continuous flow calorimeter?
$m'CL\Delta T = VI$
According to the text, what is the process called when a solid goes directly to vapor without becoming a liquid?
Sublimation
According to the text, what is the relationship between the specific heat capacities of ice and water?
The specific heat capacity of water is greater
According to the text, what is the purpose of the plateau in the temperature-time graph during heating of ice?
To indicate the melting point of water
According to the text, what is the relationship between the boiling point of a liquid and pressure?
They are inversely proportional
Which one of the following equations correctly represents the calculation for the amount of energy required for batch heating or cooling?
$Q = mass \times average specific heat \times temp change$
What is the specific heat at constant volume (Cv) defined as?
The amount of heat required to raise unit mass by unit temperature rise under constant volume
What is the specific heat at constant pressure (Cp) defined as?
The amount of heat required to raise unit mass by unit temperature rise at constant pressure
How can the specific heat of a mixture be found?
By calculating the sum of the products of the fraction of each component and its specific heat
What is the specific heat of water-rich foods approximately?
3700 J/kg. oC
What is the specific heat of oil-based foods approximately?
2100 J/kg. oC
What is the specific heat of frozen foods approximately?
2000 J/kg. oC
What is the specific heat of ice approximately?
2110 J/kg. oC
Which method is used to determine specific heat?
Method of Mixtures
Which readings are required in the Method of Mixtures to determine specific heat?
Mass of the specimen, mass of the calorimeter, mass of the fluid, initial temperature of the specimen and fluid, and final temperature of the mixture
Which one of the following equations correctly represents the calculation for the amount of energy required for batch heating or cooling?
Q = mass x average specific heat x temp change
What is the specific heat of water-rich foods approximately?
3700 J/kg. oC
What is the specific heat of oil-based foods approximately?
2100 J/kg. oC
What is the specific heat of frozen foods approximately?
2000 J/kg. oC
Which readings are required in the Method of Mixtures to determine specific heat?
ms, mc, and mf
Which method is used to determine specific heat?
Method of Mixtures
What is the relationship between the specific heat capacities of ice and water?
They are equal
What is the latent heat of fusion for water?
2110 J/kg. oC
What is the latent heat of vaporization for water?
4180 J/kg/k
According to the text, what is Newton's law of cooling?
The rate of heat loss is directly proportional to the temperature difference between the object and its surroundings
Which method is used to determine specific heat?
Method of Cooling
What is the specific heat of water-rich foods approximately?
2.0 J/kg/K
What is the latent heat of fusion for water?
540 J/g
According to the text, what is the relationship between the boiling point of a liquid and pressure?
Inversely proportional
According to the text, what is the relationship between the rate of heat loss from a sample and the rate of heat loss from a reference material in the method of cooling?
Directly proportional
What is the specific heat of oil-based foods approximately?
4.0 J/kg/K
According to the text, what is Newton's law of cooling?
The rate of heat loss from a body is directly proportional to its temperature
According to the text, what is the purpose of the plateau in the temperature-time graph during heating of ice?
To indicate the melting point of water
According to the text, what is the equation for calculating the rate of heat loss in a continuous flow calorimeter?
m'CLΔT = VI
According to the text, what is the process called when a solid goes directly to vapor without becoming a liquid?
Sublimation
Which one of the following is true about the latent heat of vaporization?
It is the amount of heat required to change a substance from a liquid to a gas at its boiling point.
What is the specific heat of water approximately?
3 J/g°C
According to the text, what is the relationship between the specific heat capacities of ice and water?
The specific heat capacity of ice is less than the specific heat capacity of water.
What is the latent heat of fusion for water?
2257 kJ/kg
According to the text, what is the purpose of the plateau in the temperature-time graph during heating of ice?
To indicate the phase change from solid to liquid.
According to the text, what is the purpose of using an electrical element in a calorimeter?
To provide a constant source of heat for the experiment.
According to the text, what is the relationship between the rate of heat loss from a sample and the rate of heat loss from a reference material in the method of cooling?
The rate of heat loss from a sample is always less than the rate of heat loss from a reference material.
According to the text, what is the equation for calculating the rate of heat loss in a continuous flow calorimeter?
Q = mλ
What is the specific heat of frozen foods approximately?
1 J/g°C
According to the text, what is freeze concentration?
The process of freezing a liquid to concentrate the solutes in the unfrozen material.
Which one of the following is true about the specific heat of water-rich foods?
It is approximately equal to the specific heat of water
What is the purpose of the plateau in the temperature-time graph during the heating of ice?
To indicate the melting point of water
What is the relationship between the rate of heat loss from a sample and the rate of heat loss from a reference material in the method of cooling?
They are equal
What is the specific heat of oil-based foods approximately?
It is higher than the specific heat of water
What is the process called when a solid goes directly to vapor without becoming a liquid?
Sublimation
What is Newton's law of cooling?
The rate of heat loss from a body is directly proportional to the excess temperature of the body above that of its surroundings
What is the specific heat of frozen foods approximately?
It is lower than the specific heat of water
Which readings are required in the Method of Mixtures to determine specific heat?
Mass and temperature of both the sample and the reference material
What is the relationship between the boiling point of a liquid and pressure?
They are inversely proportional
What is the latent heat of fusion for water?
It is not mentioned in the text
What is the equation for calculating the amount of energy required to raise the temperature of a unit mass by a unit temperature rise in batch heating or cooling?
Q = mass x average specific heat x temp change
Which one of these is true about the relationship between enthalpy and heat content?
Enthalpy is equal to heat content both above and below the freezing point.
Which one of the following equations correctly represents the calculation for the amount of energy required for batch heating or cooling?
Q = mass x average specific heat x temp change
What is the latent heat of vaporization for water?
2257 kJ/kg
What is the specific heat of water-rich foods approximately?
3700 J/kg. oC
What is the specific heat of frozen foods approximately?
3.2 kJ/kg·°C
What is the specific heat of oil-based foods approximately?
2100 J/kg. oC
What is the specific heat of water-rich foods approximately?
3.2 kJ/kg·°C
What is the specific heat of frozen foods approximately?
2000 J/kg. oC
What is the purpose of the plateau in the temperature-time graph during heating of ice?
To indicate no change in temperature during the phase change.
Which method is used to determine specific heat?
Method of Mixtures
What is the purpose of using an electrical element in a calorimeter?
To provide heat for the process of freezing.
According to the text, what is the purpose of using an electrical element in a calorimeter?
To provide heat to the fluid
What is the effective freezing time defined as?
The time required to reduce the temperature of a sample from the ambient temperature to -15°C.
According to the text, what is the purpose of the plateau in the temperature-time graph during heating of ice?
To indicate the melting of the ice
What is the change in enthalpy given by?
ΔH = ΔU - pΔV + pΔV
What is freeze concentration?
A process in which a liquid is cooled below its freezing point
What is the relationship between the specific heat capacities of ice and water?
The specific heat capacities of ice and water are equal.
How can the specific heat of a mixture be found?
By measuring the temperature change of the individual components
What is the relationship between the boiling point of a liquid and pressure?
The boiling point of a liquid increases with increasing pressure.
Test your knowledge of specific heat and thermodynamics in this quiz. Learn about the amount of energy required to raise temperature, continuous processes, and more.
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