THE RETURN OF THE MOLE.. DUNDUNDUNNNNN

ΔH is the reaction's energy change and is expressed as: kJ/ mole.

Ex. 1:
2C + H2 + 227 kJ --> C2H2

ΔH = 227kJ
      1 mol of C2H2

Ex 2: Using the same equation from above, calculate the energy relased when 2 moles of C2H2 is produced.

2 mole of C2H2   x       227kJ
                                   1 mole of C2H2

= 454 kJ of energy released

Now, you can add another section fo your mole map; between moles and energy.
Moles --> Energy = multiply by:              kJ
                                                           1 mole

Energy --> Moles = multiply by:           1 mole
                                                              kJ

So now, since you are able to convert from energy to moles, you can also convert it into grams, molecules, or number of atoms.

Ex. 3
Using the equation: 2Ba + O2 --> 2BaO + 1115 kJ
Calculate how many grams would be needed to produce 2000 kJ of energy.

ΔH = 1 mole of O2
           -1115 kJ

-2000 kJ x  1 mole of O2   = 1.7937 moles of O2
                     -1115 kJ


1.7937 moles x   32.00 g of O2   = 60 grams of O2
                           1 mole