Chapter U5, Problem 8RE

Interpretation Introduction

Interpretation: The conclusion is given for two substances from given heat of fusion of water and ethanol.

Concept introduction: Heat needed to change 1 gram of a substance from a solid to a liquid is termed as heat of fusion.

Answer to Problem 8RE

From given data boiling water needed to supply more heat than ethanol.

Explanation of Solution

Given heat of fusion for water is $\text{79}\text{.9}\text{cal}/\text{g}$ and heat of fusion for ethanol is $\text{24}\text{.9}\text{cal}/\text{g}$ . From this data water has more heat of fusion than ethanol. Thus for boiling water needed to supply more heat than ethanol.

Conclusion

Heat of fusion is the energy required to change a substance from solid to liquid. It is the amount of heat transfer required to change a substance from a solid to a liquid, usually expressed per mole or gram.