00:01
We have to balance these two equations, one in an acidic environment, the other in a basic environment.
00:08
Let's start with nitrate plus tin.
00:11
First, we're going to separate out our nitrate half equation and then our tin half equation.
00:26
So now that we got those separated, let's first balance everything but oxygen and hydrogen.
00:31
In both cases, everything's balanced.
00:35
Now let's balance our oxygen.
00:37
In our nitrate one, we have three on the left and two on the right.
00:42
So we're going to add one h2o to the left -hand side.
00:47
Now we have to add another two h's to compensate for those two that we had from the water.
00:56
Now let's take a look at charges.
01:00
For the nitrate one, we have two positives plus one negative for a net positive, and then we have zero plus zero.
01:12
So we're going to have to add some electrons.
01:15
So we're going to add one electron to the left -hand side to make everything balanced.
01:25
Now let's take a look at our tin.
01:27
We have a positive two charge on the left and a positive four charge on the right.
01:32
That means we're going to have to add some electrons to the right -hand side to bring that charge down.
01:38
So we're going to add two electrons.
01:41
Now we have to multiply that nitrate one by two to balance those electrons.
01:51
So we're going to have two electrons plus four hydrogens plus two nitrates.
01:58
That's going to yield two no2 plus two h2o.
02:07
Let's throw in our tin as well.
02:11
We don't have to worry about those electrons anymore.
02:20
We can get rid of those.
02:23
So now let's rewrite our final equation.
02:26
Sn two plus plus four h plus plus two no3 minus.
02:35
That will yield two no2 plus two h2o plus tin four plus.
02:49
Now let's move on to the basic one.
02:51
First we separate our two reactions.
02:58
One with manganese in it and then the iodine.
03:05
Let's first balance that iodine one.
03:08
We're going to put it two in front of that iodine ion on the left -hand side.
03:13
Then to the manganese half reaction, we're going to add water.
03:18
But we have to add two waters because we need two oxygens...