Ready for some.... STOICHIOMETRY!!

You might ask what's a stoichio... what?
It's stoichiometry. To break is up STOICHIO it greek for element and METRY means measurement.

Stoichiometry is about measuring the amounts of element and compound in a reaction and it's also about the study of relationship between the amount of the reactants used in chemical reaction and the products produced in a reaction.

It's confusing at first but let's try some examples!

Ex. 3C2H4 + 5O2 ---> 6CO2 + 4H2O (NOTE: make sure the chemical equations are always balance.)

There are several ways to do this, for example, you can look at the chemical formulas that stands for the number of atoms like 3C2H4 => 2C and 1 H atom or 3C2H4 = 48 g/mols. Other ways could be looking at the coefficient 3 X C2H4 = 6 carbon and 12 hydrogen.

Looking at the same example 3C2H4 + 5O2 ---> 6CO2 + 4H2O
Stoichiometry shows us the ratio 3:5:6:4. This ratio is call the mole ratio.  


3:5:6:4 can be expressed as 3 molecules or C2H4 reacting with 5 molecules of O2 producing 6 molecules of CO2 and 4 molecules of H2O. 


(Reminder: As written above all equations should be balanced because the the equation tells us the ratio of molecules in the chemical reaction.)

Oh! You thought the mole wouldn't come up eh? YOU'RE WRONG. The mole will always be where you are...jks! But as for this chapter mole still exist so don't be too excited :)

INFO THAT MAY HELP YOU:
What you need over what you have or where you're going over where you start.
 What you need       or      Where you're going      
What you have                 Where you start

 Got it? Okay, let's start the fun.

3C2H4 + 5O2 ---> 6CO2 + 4H2O

Ex. How many moles of O2 will form when 6.3 mole of H2O is taken?

6.3 mole of H2O x 5 mole of O2   = 7.9 mol of  O2
                               4 mole of H2O

Now try some examples by clicking on this link. Solutions will also be posted. Have fun and MOLES!
Practice Problem (1)
Practice Problem (2)
Solution:
Solution to Problem (1)

Still need a little more understanding of it? Check these out :D ENJOY!