Enthalpy and Energy Calculations

It's the RETURN OF THE MOLE! 

ok in all seriousness now, today we learnt about Enthalpy and how to calculate energy to moles.

Enthalpy: the total Kinetic and Potential Energy of a substance - the "heat content" of a substance.

Chemists are interested in the change in enthalpy in a chemical reaction. 

In an exothermic reaction, the enthalpy goes DOWN. It is converted into heat and released. 

In an endothermic reaction, the enthalpy goes UP. It is absorbed. 

/\H = Hproduct - Hreactant 

To find the total change in enthalpy, you just subtract the reactant from the product. 

In this picture, C is in the place where the change in Enthalpy would normally be. 

/\H = Hproduct - Hreactant 

/\H = 300 - 100 

/\H = 200 kJ

As you should already know, the unit for enthalpy is kJ, or kilojoules. 

Energy to moles: 

Here is a mole map.

Here is a mole map, with the calculations for Energy -> moles.

As you can see, to get from moles to energy, you simply multiply by the number of kilojoules/1 mole. To get from energy to moles, you multiply by 1 mole/number of kilojoules.

Wahooooo