Anyways... Stoichiometry involves particles, mass and MOLES! Well lets start off this blog/lesson with a mole map! Stoichiometry deals with quantitative relationships between a reactant and product. That is why the relations for the quantities can usually produce a ratio of some sort!
Well ok.. so how to do these calculations. Well it is easier to these calculations in steps.
The First Step: Make an equation out of the word problem, and balance it!
The Second Step: You can make a road map to help you visualize what you need to do
The Third Step: Follow the map and calculate what you need to calculate!!!
Well lets learn more about Stoichiometry by doing a few examples first.
Ex 1/ Consider this equation: 2KMnO4 + 16HCl --> 2 KCl + 2MnCl2 + 8H2O + 5Cl2
How many grams of KMnO4 will be needed to react with 2.30 moles of H2O?
Step 1 is already done for you because it is already balanced!
Step 2: 2.30 moles H2O --> moles KMn04 --> ? grams KMnO4
Step 3:
2.30
8
REMEMBER TO DO YOUR SIG FIGS!!!! ANYWAYS! That was easy right???
Well... If you are like me, and is REALLY confused...here is a pattern you can refer to!!!
grams(x)<-->moles(x)<-->moles(y)<-->grams(x)
You can start as well as go anywhere along this path, as long as you do it in the correct order!!
Now that you have this in mind.. lets start do one more example!
Example 2/
Consider this equation: 4KO2 + 2H2O --> 4KOH + 3O2
How many moles of KO2 can be made using 4.50 mole O2?
4.50
3
K.. You might THINK you had enough of Stoichiometry and moles.. but don't worry it'll come to haunt you next lesson too! Soo.. you might as well do some more practice on these sites!
http://library.thinkquest.org/10429/high/stoich/question.htm
http://www.askmehelpdesk.com/chemistry/stoichiometry-problems-176369.html
http://www.askmehelpdesk.com/chemistry/stoichiometry-questions-113202.html
WELL .. if u don't understand the way I iunno... taught the lesson... well SUCK IT UP! and... i guess you can watch this video!
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