00:01
When we're asked to find the overall enthalpy change per mole of barium sulfate formed from combining sodium sulfate and barium nitrate.
00:10
So i went ahead and put up, i'll go over here.
00:13
Here's the main equation.
00:14
We have two aqua solutions, the sodium sulfate and barium nitrate.
00:18
We're going to form some barium sulfate solid and some sodium nitrate as well.
00:22
But what we are concerned about is this particular product right here.
00:27
So we will visit that here shortly.
00:30
But we do need to realize that given we have these information or this information listed here for volume and molarity on both reactants, we need to understand that we can measure delta h given the heat of the reaction by combining the solutions because we're using constant pressure of coffee cup calerometry.
00:51
So that was discussed earlier in this unit where if we use this particular technology to make, the heat evolved on a reaction or heat absorbed depending on the type of reaction, that we can use q equals mc delta t.
01:06
And we do have the information here, delta t is 42 degrees celsius.
01:12
Heat capacity of that solution combined as 6 .37 joules per gram degree celsius, along with the density of 2 grams per milliliter.
01:21
We'll refer to that here shortly.
01:23
And if we go ahead and we do have specific heat and delta t those are two things we definitely have but we don't have this mass that's a problem but if we go ahead and figure that okay if we have two grams per one militer of solution how many grams would we have if we had a combined total of three liters the one uh the three comes from the one uh mole of sodium sulfate in the or not one more one liter of the sodium sulfate and 2 liters of the barium nitrate.
01:58
So we have a combined volume of 3 liters, and that would be equivalent to 3 ,000.
02:07
Okay.
02:07
So if we simply, that's 3 ,000 milliliters, if we simply just do some ratio mathematics, we can figure out that this x when we cross multiply is 6 ,000.
02:24
And that's 6 ,000 grams.
02:26
We have 6 ,000 grams per 3 ,000.
02:29
Milliliters of solution.
02:32
So we can go ahead and use that in our q equals mc delta t.
02:35
We'll just say 6 ,000 times 6.
02:41
I believe that's 37.
02:44
Yes, 37.
02:46
And our temperature change is 42.
02:49
That's going to give us an overall heat change of 16 .05 240.
02:59
There we go...