SL Chemistry

Energy Conversions

Hey guys!

     So, in Chemistry, we're on Chapter 5: Energetics! More specifically, we've been learning how to calculate amounts of heat energy (in kJ) produced during different combustion reactions. In other words, we look at the energy of the reactants and the products to calculate the overall energy. A combustion reaction is simply a reaction which produces energy. For example, when methane burns, heat is produced. 

Some of the key terms needed to be able to understand the energy conversions are below:

Enthalpy: Enthalpy is the amount of heat content used or released in a system at constant pressure. (http://chemwiki.ucdavis.edu/Physical_Chemistry/Thermodynamics/State_Functions/Enthalpy)

Average bond enthalpy: The average amount of energy needed to break one mole of bonds in a gaseous state.
(http://chemwiki.ucdavis.edu/Theoretical_Chemistry/Chemical_Bonding/General_Principles/Bond_Energies)

Standard enthalpy of formation: The standard amount of energy needed to create 1 mole of a compound.
(http://chemwiki.ucdavis.edu/Physical_Chemistry/Thermodynamics/Unit_I%3A_Thermochemistry/Fundamentals_of_Thermodynamics/Enthalpy)

The last thing you will need to be able to do these conversions yourself is a practice problem. I've provided some for you down below. Have fun!

A sample practice problem using energy conversions

- Giselle D.