00:01
Hello, we are going to balance some equations today.
00:08
Now i'm gonna be a little bit lazy and not write the states down, whether they're solid, liquid, gas, and so forth, because that actually doesn't matter when you're balancing.
00:18
Just to keep things as simple as possible, i'm gonna write it like this.
00:22
All right, now sometimes with these big equations, when we have you balance them, it can be a little hard to keep track of how many you have of each one.
00:30
And so i recommend doing a kind of a way to keep track of them as you go until these become really comfortable and you don't need to do this anymore.
00:43
Some people always do this.
00:44
Some people just do it in the beginning.
00:46
But we're just gonna count up how many of each one we have.
00:49
So calcium on the left -hand side, we've got three.
00:52
Phosphorus, we've got two.
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Hydrogen, we've got two.
00:57
And oxygen, we've got one.
01:00
Next one, we've got calcium, we've got one of those.
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Phosphorus, one.
01:08
Hydrogen, now there's two hydroxides, which means there's two separate oh groups.
01:13
So there's two hydrogens coming from this part right here.
01:17
And then there's another three hydrogens right there.
01:20
So that's a total of five.
01:24
And then with the oxygen, it's the same logic.
01:26
We have two copies of the oh groups.
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So that means two oxygens.
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And the whole point is to just make it so the numbers on both sides equal.
01:35
We want the same number of each atom.
01:37
With this one, i didn't see anything that was gonna heavily trip us up, which means we can just kind of start wherever we want.
01:43
We might as well start with the calcium.
01:45
Got three and one.
01:47
Now when you're balancing, the only thing you can change is the number out front.
01:53
We call those coefficients.
01:57
Those are the only things you can change when you're balancing.
01:59
For example, i could not put like a three right there after the calcium, like ca3, because that changes what the compound is.
02:08
But you can put numbers out front.
02:10
That changes how many of that compound you've got, but it's still the same exact compound.
02:14
There's just like three copies of it.
02:17
Okay, so that changes the calcium to three, but it also impacts other things as well, because if we have three compounds and each one has two hydroxides, three times two, we have a total of six oh groups, which means six oxygens and six hydrogens plus the three that are over here.
02:38
So that's a total of nine hydrogens.
02:44
All right, next step, let's look at the phosphorus.
02:53
We've got two and we've got one.
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So let's put a two in front of the ph three.
02:59
That'll get our phosphorus up to two.
03:01
It will also impact our hydrogens, because now we've still got the six hydrogens from the calcium hydroxide plus another two times three, which is six for a grand total of 12.
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Last thing to do is to balance our hydrogens and oxygens.
03:23
And if you actually balance one of them in this case, it balances the other.
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So let's look at the hydrogens.
03:27
We've got two and then we've got 12.
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Easiest way to deal with that is gonna be to put a six in front of the hydrogen.
03:35
Six times two is 12.
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And then six times just the one oxygen gets that up to six.
03:43
So we have actually knocked out both hydrogen and oxygen in that one.
03:47
So there's your balanced equation.
03:52
Let's write out the next one.
03:53
We're doing aluminum hydroxide plus sulfuric acid to make aluminum sulfate and water.
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Go ahead and scroll down.
04:11
Just like we did on the last one, we're gonna take stock of how much we have.
04:16
Okay.
04:16
Now there's some tricks that you can do to make your life a little bit easier on this problem.
04:22
Right? and one of them is to keep an eye out for polyatomic ions that show up on both sides.
04:28
For example, the sulfate, so4, which is sulfate, shows up on the left and then it shows up on the right and it's still intact.
04:37
It's still so4, right? that means instead of counting those sulfurs and oxygens separately, we can just track them as so4.
04:46
So let me show you what i mean.
04:49
We're gonna do aluminums, we're gonna do oxygen and hydrogen, and then we're gonna do sulfate like that.
04:58
The hydroxide is also a polyatomic ion, but it doesn't show up the same.
05:04
It shows up in the form of water later, which isn't the same format.
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So we're not gonna track hydroxide that way.
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We're just gonna do the sulfate.
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This is gonna make your life a lot easier, especially when it comes to tracking how many oxygens you have.
05:17
And we'll see that in future examples as well where we do that.
05:20
So we're gonna do aluminum, oxygen, hydrogen, and sulfate.
05:24
I try to keep them in the same order on both sides, like aluminum, oxygen, hydrogen, sulfate, so they match.
05:30
Okay, let's fill them in.
05:32
On the left, we have one aluminum.
05:35
We have three times one, which is three oxygens, three hydrogens plus two more, so that's five, and then one sulfate, okay? on the right -hand side, we've got two aluminums, okay? ignore the oxygens and the sulfate, go over to the water.
05:58
We've got one oxygen, two hydrogens, and three sulfates.
06:04
Right, we're gonna work through the same process we did in the last one.
06:10
Just let me clean it up a little bit.
06:14
There we go.
06:16
We can start with whatever we want to, in this case, aluminum, we've got one, and then we've got two.
06:23
So let's put a two in front of the aluminum here.
06:26
Changes that to two.
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And then we need to check how many oxygens and hydrogens we have because that changed those values.
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So now there's two times three, which is six.
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So now there's six oxygens.
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Remember, we're ignoring the sulfate.
06:42
We're pretending like the oxygen sulfate only belongs to sulfate.
06:47
We have six hydrogens there plus the other two, so that makes that, what, seven? all righty, and now our aluminums are balanced.
07:00
Next, we can go ahead and take a look at, who do we want to look at? honestly, we can do any of them.
07:09
Oxygen, sure, why not? oxygen, there's six on the left and then one on the right.
07:18
So we could put a six in front of the water.
07:22
That would change that to six.
07:23
It would also impact the hydrogens on that side.
07:25
Now we have six times two per water, so that's a total of 12 hydrogen.
07:32
Okay, so now the oxygens are taken care of.
07:34
We're just kind of moving down the list.
07:38
Now let's look at hydrogen.
07:46
Actually, let's do sulfate because oftentimes when you see an atom showing up, and when you see a single element showing up in more than one place, like we have hydrogens here and here, when they show up more than once on one side of the equation, leaving them to last will commonly make your life easier.
08:03
So let's do the sulfate and then we'll take care of the hydrogen last.
08:06
A lot of the times, if you take care of everything else first, like the hydrogen will take care of itself.
08:11
Like it'll be fixed.
08:12
Okay, so we have three sulfates and then we only have one sulfate.
08:16
So we need to have three there, i think.
08:21
Yes, because that'll change the sulfate to three and that impacts the hydrogens.
08:26
So we've got six hydrogens from right there and then we've got another two times three.
08:32
We have another six there.
08:33
So there's six and there's six for a total of 12, which has in fact fixed the hydrogen as well.
08:40
Perfect, so there's that one done.
08:43
All right, i might go a little bit quicker on these other ones as we're getting them down.
08:49
We've got silver nitrate plus sodium carbonate goes to silver carbonate and sodium nitrate.
09:00
We're gonna track just like we did before...