ALEKS: Calculating a molar heat of reaction from formation

How to solve the ALEKS problem: Calculating the molar heat of reaction from formation

[EmilySmith-hnvd]

I truly hope you get good $ for this channel bc you are legit the best. I watch your videos alone to learn every new concept I need for this wretched ALEKS program. You are a godsend.

[noneatthistime]

When the youtube example is that last problem you have on a 3 of 5 so you can move on. LOL

[tonytouma]

This is the best YouTube channel of all time

[bethanyjoycruz]

The ALEKS explanation made me do more work than I really needed to, thank you for posting this video I am so grateful.

[allyroy]

i love you roxi. you have saved my chem grade <3

[lilly]

I keep getting it wrong for some of them because it uses "Hess's law" which somehow makes the stoichiometric coefficient negative in front of the delta H values. This happened to me more than once when I was given a reactant with a delta H value of 0. I'd follow what you said, "products - reactants" but then again there was that sign change for some reason in the stochiometric coefficient, which Im not sure why and ALEKS does poorly to explain. Do you know the reason?

[raulyjimenez]

In my case, the 1st column is the one that i am using and the calculations are coming out correct. The first time i used the second column and my answer was wrong. I was curious, so i started lining up the text of the question to make sure that this was the same "type" of question, and it is. So now i am wondering, when would I use the degree of G opposed to degree of H or degree of S. I apologies if i stated the different data types incorrectly, hopefully, you are able to decipher what i am saying.

[austin]

The thing that makes no sense to me is that sometimes ALEKS is saying I should use a negative coeefficient but it doesnt way why. IE for this problem, it would be something like using a -3 for one of the CO2 and multiplying it like that (it didnt in this issue but just using that as an example) But it doesnt state how or why it should be negative, it just uses a negative

[Miistik]

correction you don't have to use the values in the second column of aleks. It is the first one, the one that says "delta hf".

[moalzaben]

I swear to god Aleks is just taking the piss! I can’t figure out which row does it want it’s not clear. They don’t even state which row.

It gave me C2H2(g)+2H2—->C2H6(g) I tried the first column it gave me incorrect because I followed your vid by using the 2nd column for my first problem which was 2HNO2(g)+O2(g)—>2HNO3, but for some stupid reason the explanation showed that it used column 1. Why? I have no clue. Aleks is just being stupid and unhelpful.

[jasonthompson]

WRONG!!!! According to ALEKS that is incorrect. Don't get me wrong, that is also how I learned it but according to ALEKS it is wrong. Example: C2H5OH(l) + 3O2(g) = 2CO2(g) + 3H2O(l) this should equal -580kJ, CORRECT ME if I am wrong. However, ALEKS says it is-1367kJ