00:01
We are asked to calculate the concentration of all species in a sodium sulfite solution.
00:06
We're told that we have a 1 .62 molar solution and our ka1 is 1 .4 times 10 to the minus 2 and this one is 6 .3 times 10 to the minus 8.
00:26
Okay, let me think about this for a moment please.
00:34
So we have several things happening here.
00:39
First, this is going to dissociate into two na's and pluses and an so3 minus.
00:55
Okay, so my concentration of my sodium ion will be 1 .62 times 10 oops 1 .62 molar na2so4 and that's moles per liter times 1 to 2 moles of na plus per na2so4 and this will equal 3 .24 molar.
01:45
So my na plus concentration will be 3 .24 molar.
01:55
There's one.
01:56
I'm going to do this in case i need to find it later.
02:00
Now our so3 is now in water and it is going to go into equilibrium with hso3 minus and oh minus.
02:19
So let's find we're given we're going to have to find our kb and that is going to equal 1 .4 times or 1 .0 times 10 to the minus 14 divided by 1 .4 times 10 to the minus 2.
03:02
Okay, so 1 times 10 to the minus 14 divided by 1 .4 times 10 to the minus 2 is 7 .14.
03:24
I don't know which one to use here.
03:31
Oh, this is going to give me kb2.
03:36
So i think here i need to use 6 .3 times 10 to the minus 8.
03:45
1 times 10 to the minus 14 divided by 6 .3 times 10 to the minus 8.
03:53
That's 1 .587 times 10 to the minus 7.
04:05
Okay, so now i should have done this somewhere else.
04:11
So now i've got my so3 2 minus plus h2o and that's hso3 and oh.
04:23
This will be 1.
04:24
What is this? this was 1 .62.
04:37
Yes, 1 .62.
04:41
So my ksp expression will be 1 .587 times 10 to the minus 7 equals 1 .62 minus x.
05:03
Let's see if that makes sense to me.
05:06
And i'm going to ignore this.
05:14
So i'm going to just omit that.
05:18
So i'm going to take second square root of 1 .587 times 10 to the minus 7 times 1 .62.
05:38
1, oops, 1 .587.
05:54
Let me try this again.
05:58
1 .587 times 10 to the minus 7 times 1 .62...