00:01
All right.
00:02
So what we are looking at here is kind of a ionic bonding related problem.
00:09
I want us to write the reaction of sodium with a couple of different elements and compounds.
00:16
Right.
00:17
So the first thing is asking us is to write the reaction for sodium and oxygen if they were combined together.
00:28
Okay.
00:29
We know in the real world that oxygen doesn't just come as a free element.
00:35
Element like this.
00:35
It comes in the form of oxygen gas as o2.
00:40
But what's going to be happening here is that the sodium will be combining with our oxygen to make sodium oxide.
00:50
And what we want to know is what ratio they're going to be combining in.
00:56
Right.
00:56
So we know what this formula over here is going to be.
00:59
To figure that out, we need to look at what the charge of each of these ions is.
01:04
If you look on the periodic table and finds sodium, you'll see that it is in the far left column, meaning that it has one valence electron.
01:12
So when it becomes an ion, it ends up as n -a -plus -1, because it gives that one electron away and has a charge of positive one.
01:23
If it's going to form an ionic bond with oxygen, well, when oxygen ionizes, it needs to gain two electrons, so it becomes o -minus 2.
01:33
All right, so this compound over here we need to make sure is neutral, which means that if if each sodium has a charge of positive one, then each oxygen has the charge of negative 2, we would need two of these sodium to cancel out the charge of the oxygen.
01:49
So our compound over here would be na2o.
01:52
This is sodium oxide.
01:54
And the last thing we've got to do is make sure this equation is balanced.
02:00
Okay.
02:01
On the left side of our reaction here, we actually have two oxygens because oxygen comes, you know, bonded to itself like this.
02:09
And on the right side, we only have one of them.
02:11
So what we'd have to do is put in our coefficient here to make sure we have two total oxygens.
02:18
That also affects the number of sodiums we have.
02:20
Two times two would be four, which means over here we would need a coefficient of four.
02:26
So this would be your final answer for part a.
02:35
Okay, part b is kind of the same idea...