Concept explainers
Interpretation:
The amount of energy must be removed from the tray to reduce the temperature from
Concept introduction:
The amount of energy required to change the state of a substance is known as enthalpy. It is the different in the energy of final and initial state of a substance. The negative and positive sign of enthalpy indicates the energy released and energy absorbed, respectively, during the phase change.
Answer to Problem 110E
Amount of energy that must be removed from the tray to reduce the temperature from
Amount of energy that must be removed to cool the water from
Amount of energy needed to freeze the water is
Amount of energy removed to when temperature of ice is decreased from
Total energy removed or released is
Explanation of Solution
The amount of heat required to decrease the temperature of aluminium from
Where,
•
•
•
•
The mass of the sample is
The given final temperature is
The given initial temperature is
The specific heat of aluminium is
Substitute the values of mass of the sample, final temperature, initial temperature and specific heat of aluminium in equation (1).
Negative sign shows that energy is released during decrease in temperature of aluminium from
Therefore, amount of heat required to decrease the temperature of aluminium from
The amount of energy removed to decrease the temperature of water from
The given value of mass of water
The given value of final temperature
The given value of initial temperature
The specific heat of water is
Substitute the values of mass, final temperature, initial temperature and specific heat of water in equation (1).
Therefore, amount of energy removed to decrease the temperature of cool water from
The amount of energy required for phase transformation is calculated by the formula shown below.
Where,
•
The heat of fusion of water is
Substitute the mass and heat of fusion in equation (2).
Negative sign indicates that energy is during the freezing process.
Therefore, amount of energy required for phase transformation is
The amount of energy removed to decrease the temperature of water from
The given value of mass of water
The given value of final temperature
The given value of initial temperature
The specific heat of ice is
Substitute the mass, final temperature, initial temperature and specific heat of water in equation (1).
Therefore, amount of energy removed to decrease the temperature of ice from
The total amount of energy released is shown below.
The amount of heat released to decrease the temperature of aluminium tray from
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Chapter 15 Solutions
Introductory Chemistry: An Active Learning Approach
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