CHEM 1A03 Lecture Notes - Lecture 16: Electron Affinity, Joule, Fluorine

• School: McMaster University
• Department: Chemistry
• Course: CHEM 1A03
• Professor: David Brock

Document Summary

Latent, or hidden, heat of fusion enthalpy energy entering the system used to change phase instead of changing temperature phase change occurs at constant temperatures. Assume dealing with changes occurring at constant pressure and therefore enthalpy h and heat flow, qp, are equal. When we have a solid and add energy (heat flow), get increased temperature. Once we hit the phase change, there is no temperature change and we have a mixture of solid and liquid until all the solid is melted. To calculate this change in enthalpy we multiply the molar heat of fusion by the number of moles of solid that are melted. Once everything is melted, any energy added results in temp increase (same thing for liquid except heat of vaporization) Bon dissociation energy refers to the amount of energy required to break 1 mole bonds in gas phase.