00:02
We are asked to consider the reaction i've written here.
00:05
Equus lead nitrate reacts with potassium iodide and the potassium, excuse me, the lead -2 iodide precipitates.
00:16
We're given the following of information.
00:19
We have 75 .0 milliliters of 0 .10 molar lead to nitrate.
00:34
We mix it with 100 milliliters of 0 .190 molar potassium iodide.
00:48
We are asked for part a, the mass of lead -2 iodide formed.
01:03
And for part b, we are asked the concentration of pb2 plus at the end, the k -plus, the nl3 minus, and the eye concentrations.
01:24
We need to know the malarity of these four species.
01:30
This is actually not as bad as i thought of it was going to be.
01:33
So this is limiting reactant problem.
01:37
And let's start by looking at our lead iodide, lead two iodide, lead to nitrate, i should say.
01:54
We're going to take our volume and liters times our malarity, and then i'm going to convert that to mass of our lead to iodide that will form.
02:26
It's a one -to -one ratio.
02:28
In the mold of mass my lead iodide was 461 .0 .01 grams per mole.
02:57
This equals 3 .45, i can't read my writing here, 3 .4576.
03:14
We'll worry about rounding later.
03:23
Then let's figure out how many moles or how much would be formed for the k -i.
03:34
And here we've got 100 milliliters, which is 0 .1 liters, 0 .190 moles per liter.
03:56
Here we'll have a 2 to 1 mole ratio, and our molar mass is still 4601 grams per mole, and this equals 4 .3796 grams of pb .i 2.
04:31
We can say that this is limiting and this will be the mass of lead iodide.
04:38
So the answer for a to three significant figures will be 3 .46 grams of lead -2 iodide will be formed.
04:55
And we can start looking at part b.
05:00
For a lead -2 iodide, or a lead -2, all of our lead -2, since that's limiting, will be converted to the lead -2 iodide, so our concentration will be zero.
05:17
Then let's do what's next.
05:22
I did n .o3 next...