Stoichiometry Calculations

As previously mentioned... stoichiometry is calculations which involve chemical reactions!

Just in case you have forgotten what chemical reactions may look like (which i doubt ;) this will help!

From our studies with moles, we have learned quite a few different conversions which involve them.

This chart sums up mole conversions, before our virgin ears ever heard the word stoichiometry:




Stoichiometry simply adds one more step to this simple conversion chart.

In a balanced chemical reaction, once given the mass, particles or volume of either the reactant or product; a chemistry 11 student can then find the mass, particles or volume of any other reactant or product!

How is this possible?!

Well since we know how many moles of a certain substance per so many moles of another substance, we can use this as a conversion.

For example in the balanced chemical equation:

2 Fe + 3 Cl₂ = 2 FeCl_{3; 
where we know there are 123.4 grams of iron (Fe), we can find the amount of product, (FeCl3):}


123.4 g Fe x 1 mol Fe     x  2 mol FeCl3   x  162.3 g FeCl3  = 717.8 g FeCl3


                    55.8 g Fe        1 mol Fe              2 mol FeCl3

Remember this concept can be applied to any sort of calculation involving a reaction; given you remember some important facts!
                                          Such as: Volume at STP (22.4L), M = moles / litres


Here`s a website with in depth information, for our blog`s eager learners!

  http://www.shodor.org/unchem/basic/stoic/