00:01
To do this problem, i'm going to start with the hydrogens because they only appear once on each side of the equation.
00:09
So i'm going to add a one here to say that for every one of these molecules, i need two of these molecules such that the number of hydrants is the same.
00:20
So now i have for hydrogen, 12 on the left, 12 on the right.
00:27
You don't have to use these numbers here on the bottom.
00:29
I find that for some students that helps them keep track of all their elements.
00:34
Now we'll do a count of the remaining elements.
00:37
For carbons, there's six.
00:38
Oxygen, there's six on the left -hand side.
00:41
Carbons, there's four there and one there.
00:46
So i have five carbons.
00:48
And for oxygens, i have two here and another two here.
00:52
So that is four.
00:56
Now notice my carbons and my oxygens are not balanced, but the only species that i can change at this point is, carbon dioxide.
01:04
So that is what i will do.
01:06
I need one more carbon on the right hand side.
01:10
So to do that, i'm going to add a two right here.
01:14
What that does is it adds one more carbon.
01:17
So now i've gone from five to six.
01:19
And my total number of oxygens is two here and four there.
01:25
And now i have six oxygen and notice that that fixes the elements that were unbalanced so now this reaction is balanced.
01:40
Next i have this other reaction.
01:43
I'm going to start with the carbon atoms.
01:50
I could potentially start with the hydgens, but let's start with the carbons.
01:54
I would like to leave the oxygen for the end because there's a single element.
01:59
It's a standalone element and sometimes those are easiest to balance at the end.
02:04
So i'll start with the carbons first.
02:07
There are six on the right.
02:09
So if i have one of these, i presume it's the sugar molecule, then i'm going to need a six in front of carbon dioxide.
02:16
So for carbon, i have six on each side now.
02:19
That is balanced.
02:21
For oxygen, i have 12 here, 13 there.
02:31
13.
02:32
And on the right hand side, i have six and eight...