00:01
We are asked to calculate the ph of a 0 .20 molar ammonium chloride solution.
00:07
We're given the kb.
00:10
Okay, so i've got everything in the world i need to know here.
00:12
Let's go ahead and start writing some equations out.
00:16
So this will go into equilibrium with h3o plus and nh3.
00:28
So my ka for this expression will be equal to h3o plus times nh3 and we'll divide that by our nh4 plus.
00:45
Okay, so i'm gonna, i've got my kb, so my ka will equal 1 times 10 to the minus 14th divided by 1 .8 times 10 to the minus 5th.
00:58
And this will equal, i've done this about a million times, i think it's 5 .55.
01:10
Yes, so i'm gonna go 5 .56 times 10 to the minus 10.
01:17
Now let's do a nice table.
01:21
I'm gonna cheat a little bit on this one, whoops, because i don't care about my water, just for brevity...