Videos

Balancing Chemical Equations/ Chemical Reactions and Stoichiometry

Added Jun 09, 2017 •

Copy this URL:
Embed code:	<iframe class="edlio-embed-player" type="text/html" width="640" height="360" src="//colliervillehs.colliervilleschools.org/apps/embed/?v=150190" frameborder="0" allowfullscreen></iframe> Change dimensions

Show Transcript

balancing Chemical Equations is one of those Concepts in chemistry that often confuses people but I think if we will see if we if we work through this carefully in methodically we also appreciate the art of balancing chemical equations that it's actually not too bad so far so what is a cool equation well this is a chemical equation right over here it's describing a reaction so if I take an atom of aluminum and I added to a. oxygen molecule for molecule that has two oxygens with it under the appropriate conditions they will react to form aluminum side and the aluminum oxide molecule has two aluminum atoms and three oxygen atoms and so you might say okay well whatever what's the balancing this all about I have a chemical reaction what do I have to balance if you look carefully you might notice that you don't have the same number of each atom on both sides so for example right over here on the left hand side how many aluminum's do we have Wella left hand side we have one aluminum how many do we have on the right hand side on the right can side we have to aluminum's it's aluminum just can't appear out of thin air by virtue of some magical reaction you have to have the same amount of aluminum Zahn size in the same thing is true for the Oxygen's over here on the left hand side we have two oxygens they form one. Oxygen molecule but that has two oxygen atoms and it over here in the aluminum oxide molecule we have three we have three oxygen atoms so once again we can't just have a miraculously an oxygen atom appear for out of out of nowhere so we have to balance the number of aluminum this number in this number should be the same and we have to balance the number of oxygen this number and that number should be the same so how do we do that one thing might be to say okay if I've got to aluminum here and I have one aluminum here or why don't I just double the number of aluminum's right over here so I can just write it to him in front of it so now this says to aluminum so I no longer have one aluminum me right now have two aluminum's and so it looks like the aluminum's are balanced and they are indeed a balanced but still we have an issue with the oxygen over here after Oxygen's over here I have three oxygens so one thing that you might say is okay well how do I go from 2 to 3 I can x 1 and 1/2 so I could * 1.5 + If I multiply 1.5 x 2 well that's going to be 3 so now I three oxygen atoms on this side and three oxygen atoms on this side but the convention is is a we don't like writing 1 and 1/2 MI we don't like having this notion of a half molecule which is kind of this bizarre notion we want whole number molecules so what can we do well you can imagine this makes it very similar to what you did in algebra and algebraic equations we just can multiply both sides by the same number that gets rid of I'm having in this fraction or this decimal here so if we multiply both sides by two we're going to do that this is going to be a for this is going to be at 3 this is need to be a to ride over here so let me do that let me multiply both sides by two two set of two aluminum atoms let me have for aluminum actually I'm just write the account equation first in the form that it was before so I had a Lumina plus dioxygen a molecule of two oxygens yielding reaction these are the reactants this is the product  aluminum aluminum aluminum oxide what I'm saying here is to get rid of this 1.5 to turn it into a whole number let's multiply all of these all of the number of molecules by 2 and hear there's implicitly there's implicitly a one in a different color there is implicitly a one right over you're so smart why all these by 2 so 2 x 2 is that same color 2 times two is four that's not the same color two times tube is for 1.5 * 2 is 3 and then 1 X - 1 * 2 is 2 and verify how many Lumens do we have on each side will I have for aluminum atoms on the left hand side and how many do I have on the right hand side I have four aluminum atoms how many oxygens do I have on the left hand side I have three molecules of dioxygen each molecule has two oxygen atoms so I have six oxygens on the left and I have two times three oxygens on the right wife six oxygen so my equation is now balanced

Uploaded by Michelle Martin.

Videos

Balancing Chemical Equations/ Chemical Reactions and Stoichiometry

More videos from Michelle Martin