Calculating Enthalpy of Fusion

Oct 13, 2025 by wbrum.org 74 views

Introduction

In the field of chemistry, calorimeters are used to measure the heat energy absorbed or released during various chemical reactions and physical changes. One of the key concepts in calorimetry is the enthalpy of fusion, which is the amount of heat energy required to change a substance from its solid state to its liquid state at its melting point. In this article, we will explore the concept of enthalpy of fusion and how it can be calculated using data from a calorimeter.

What is Enthalpy of Fusion?

Enthalpy of fusion is a measure of the energy required to change a substance from its solid state to its liquid state at its melting point. This energy is typically absorbed by the substance as it changes from a solid to a liquid. The enthalpy of fusion is an important property of a substance, as it can be used to predict the behavior of the substance in various chemical reactions and physical changes.

Calculating Enthalpy of Fusion

To calculate the enthalpy of fusion of a substance, we need to know the amount of heat energy absorbed by the substance as it changes from a solid to a liquid. This can be measured using a calorimeter, which is a device that measures the heat energy absorbed or released during a chemical reaction or physical change.

In this problem, we are given that 6.68 kJ of heat was absorbed when 20 g of ice melted. To calculate the enthalpy of fusion, we need to divide the amount of heat energy absorbed by the mass of the substance that changed state.

Calculating Enthalpy of Fusion of Ice

To calculate the enthalpy of fusion of ice, we can use the following formula:

Enthalpy of fusion = Amount of heat energy absorbed / Mass of substance that changed state

In this case, the amount of heat energy absorbed is 6.68 kJ, and the mass of the substance that changed state is 20 g. Plugging in these values, we get:

Enthalpy of fusion = 6.68 kJ / 20 g = 0.334 kJ/g

Converting Units

To convert the units of the enthalpy of fusion from kJ/g to J/g, we can multiply by 1000, since there are 1000 joules in 1 kilojoule.

Enthalpy of fusion = 0.334 kJ/g x 1000 J/kJ = 334 J/g

Conclusion

In conclusion, the enthalpy of fusion of ice is 334 J/g. This value can be used to predict the behavior of ice in various chemical reactions and physical changes.

Answer

The correct answer is B. 334 J/g.

Additional Information

The enthalpy of fusion of ice is an important property of ice, as it can be used to predict the behavior of ice in various chemical reactions and physical changes.
The enthalpy of fusion of ice is typically measured using a calorimeter, which is a device that measures the heat energy absorbed or released during a chemical reaction or physical change.
The enthalpy of fusion of ice is a measure of the energy required to change ice from its solid state to its liquid state at its melting point.

References

Atkins, P. W. (2018). Physical chemistry. Oxford University Press.
Chang, R. (2015). Chemistry. McGraw-Hill Education.
Petrucci, R. H. (2016). General chemistry: principles and modern applications. Pearson Education.
Enthalpy of Fusion: A Comprehensive Q&A Guide =====================================================

Introduction

In our previous article, we explored the concept of enthalpy of fusion and how it can be calculated using data from a calorimeter. In this article, we will provide a comprehensive Q&A guide to help you better understand the enthalpy of fusion and its applications.

Q: What is enthalpy of fusion?

A: Enthalpy of fusion is a measure of the energy required to change a substance from its solid state to its liquid state at its melting point.

Q: Why is enthalpy of fusion important?

A: Enthalpy of fusion is an important property of a substance, as it can be used to predict the behavior of the substance in various chemical reactions and physical changes.

Q: How is enthalpy of fusion measured?

A: Enthalpy of fusion is typically measured using a calorimeter, which is a device that measures the heat energy absorbed or released during a chemical reaction or physical change.

Q: What is the unit of enthalpy of fusion?

A: The unit of enthalpy of fusion is typically measured in joules per gram (J/g) or kilojoules per gram (kJ/g).

Q: Can enthalpy of fusion be negative?

A: No, enthalpy of fusion is always positive, as it represents the energy required to change a substance from its solid state to its liquid state.

Q: What is the difference between enthalpy of fusion and enthalpy of vaporization?

A: Enthalpy of fusion is the energy required to change a substance from its solid state to its liquid state, while enthalpy of vaporization is the energy required to change a substance from its liquid state to its gas state.

Q: Can enthalpy of fusion be used to predict the behavior of a substance in a chemical reaction?

A: Yes, enthalpy of fusion can be used to predict the behavior of a substance in a chemical reaction, as it provides information about the energy required to change the substance from its solid state to its liquid state.

Q: How is enthalpy of fusion related to the melting point of a substance?

A: Enthalpy of fusion is related to the melting point of a substance, as it represents the energy required to change the substance from its solid state to its liquid state at its melting point.

Q: Can enthalpy of fusion be used to predict the boiling point of a substance?

A: No, enthalpy of fusion is not directly related to the boiling point of a substance, as it represents the energy required to change the substance from its solid state to its liquid state, not from its liquid state to its gas state.

Q: What is the significance of enthalpy of fusion in everyday life?

A: Enthalpy of fusion has significant implications in everyday life, as it affects the behavior of substances in various chemical reactions and physical changes, such as the melting of ice in a refrigerator or the boiling of water in a kettle.

Conclusion

In conclusion, enthalpy of fusion is an important property of a substance that represents the energy required to change the substance from its solid state to its liquid state at its melting point. It has significant implications in various fields, including chemistry, physics, and engineering.

References

Atkins, P. W. (2018). Physical chemistry. Oxford University Press.
Chang, R. (2015). Chemistry. McGraw-Hill Education.
Petrucci, R. H. (2016). General chemistry: principles and modern applications. Pearson Education.