Enthalpy Calculation

Calculate how much energy you need or you will produce in a reaction or how much reactants you need to produce a certain amount of energy
  
Mole conversion is required in this lesson

Eg. Calculate the amount of energy released when 1.50 moles of Carbon is reacted to form the product in this reaction: 
           4 C + 6 H2 + O2 --> 2 C2H5OH + 470 KJ

Step 1.
Convert delta H in the form you need
remember a minus sign for exothermic reaction

-470 KJ     
4 mol of C

Step 2.
Put in the equation and reduce to the unit you want
calculate the answer correctly

1.50 mol of C x -   470 KJ         = - 176.25 KJ
                          4 mol of C

Step 3.
make sure you have the correct number of sig, fig.
don't forget the unit!

-176.25 KJ --> -176 KJ

A: 176 KJ of energy is released