ChemistryWiki | RecentChanges | Preferences
- You need to be able to locate on the heating curve the following:
- Units of x- & y- axis
- Solid, liquid and gas phase
- Heat of Fusion and Heat of Crystallization
- Heat of Vaporation and Heat of Condensation
- Boiling point, condensation point, melting point and freezing point
- Critical temperature and critical pressure
- Latent heat and sensible heat
- The equation for latent heat delta H = (m)(c)(delta T) and delta H = (Heat of Fusion)(delta T)
- Mass of substance and pressure that we are heating his substance at.
- You will need to be able to calculate the heat needed for the following:
- 1.Change in temperature when you go through a non-phase change or you stay in the same phase(called sensible heat).
- You use deltaH = (m)(c)(delta T)
- 2.During a phase change, no temp change (called latent heat)
- You use delta H = (Heat of Change Phase Name)(mass of substance that changed phase)
- 3.When you go through both a phase change and non-phase change
- The heats are additive. So you calculate the heats using the appropriate equations and temp and then sum all heats to get the overall heat.
- This is difference than the tranferring of heat from one body to another (e.g. Heat of Fusion of Ice Lab) where the heat value changes sign to indicate that the new system is either absorbing or releasing that amount of heat).
- An example is in the above website. However, you need to show all units, etc. The website example is not as detalied here as we need to be.