00:01
Okay, so the question asks you to balance the equation.
00:06
So, the first one, you have the sodium 2, chromium 2 -07, react with sodium iodide, and react with nitric acid, and forms the chromium nitrate, and the form the chromium nitrate, and the sodium iodide.
00:40
Iodate here.
00:43
So the first thing you look at the crash reaction you'll find it's a redux reaction.
00:49
So when you deal with redux reaction the easiest way to balance equation is to look at the electron transfer.
00:56
So first let's determine which one is reacted, which one has the oxidation state change.
01:04
So of course chromium has changed oxidation states and iodine has also changed the oxidation state here.
01:12
So the chromium initial has a valent state of, let's see, look at the equation you'll find it has a valent state of plus 6.
01:21
And after reaction, it becomes plus 3.
01:27
So each chromium atom actually transfer gains three electrons here.
01:36
And for the iodine in the reaction reactant, initial it has a minus 1 charge.
01:45
Minus 1 valence for the product it becomes iodate so this one has a minor has a actually plus 5 charge so in this case you'll find out that the charge transfer it loses it loses actually 6 electrons for them so what's the maximum multipliers for 3 and 6 it's so for the whole reaction, that should be six electron transferred.
02:25
To satisfy that, you need two chromium.
02:28
So in the initial reactant, this one compound already has two chromium, so that's fine.
02:35
But for the product, there's only one.
02:38
So you need to actually times two here.
02:42
So now you find the charge transfer is balanced.
02:46
And now we can try to balance the element here.
02:50
So you'll find that you actually need some, what you need here, you need oxygians here, right? so initially you have, in the reactant, you have 7 plus 3.
03:08
You actually have about 10 oxygen, right? and in the product area, you actually have 18 plus 3, a 21 oxygen.
03:24
So the auction is not balanced here.
03:26
So we need to figure out a way to balance the oxygen.
03:31
Maybe the oxygen is not an easy way to balance.
03:35
The easiest one to balance is sodium here, right? the sodium, initially you have three sodium, but in the end, now you only have one sodium.
03:45
So that would be other compound contains sodium, which will be here, i believe, would be sodium nitrate as a product.
03:55
And here you need 2 sodium nitrate to balance the sodium element and in this case i believe all the oxygens are counted in the product so oxygen let's count them you have 9 oxygen so here you have 18 oxygen right you have 18 oxygen here there's 3 oxygen here there 6 oxygen here so in total in the product parts you have actually 27 oxygen.
04:37
So in this case, you will need, right? you will actually need that much of the oxygen.
04:45
So let's look at them...