Hess's Law and Heats of Formation

How can we calculate the enthalpy change of a reaction without doing it? There are two easy ways! This is how we can make sure a reaction won't explode in our faces!

Check out "Is This Wi-Fi Organic?", my book on disarming pseudoscience!

[ProfessorDaveExplains]

Sorry guys, there's an error! At 1:26, the second reaction with carbon dioxide as a reactant should have a change in enthalpy of positive 566 kJ. That changes the answer from what I've shown so please make a note of it. Luckily this error doesn't change the algorithm used, so apart from that you can still apply this concept to any set of reactions as shown here!

[makenzy]

This channel is great! I get frustrated when I have to watch a 10-30 minute video just to explain a specific concept when you can just explain in it in less than 5! Really appreciate it

[crusher]

They just "taught" us this today and I was confused af and I'm so happy to have found a Professor Dave video on this. You never let us down man. From students worldwide, we love you!

[karen]

I have been thinking of how amazing he explains complex topics and makes everyone understand for ages and now I got the answer. He speaks in a rhyme, uses emphasizes perfectly, and allocates us time to understand while speaking.

[sausagelicker]

You are single-handedly carrying my grade right now

[albertotamayo]

i love you so much man... I've been struggling to understand the Hess Law for months now and you are just a life saver!! You just got me subscribed to your channel

[Anigmus_]

My high school chem teacher always called you hairy chest guy

[xAanesaCutiex]

you help me more than my professors sometimes thank you

[bchaotic]

You are an actual life saver, I am like 20% sure I have a quiz on this stuff tomorrow (it is currently 12:30am), and I didn’t understand it before now

[kimieerojas]

My chemistry teacher stresses me so bad, she doesn't know how to explain her classes and many of my friends end up confused with the lessons. This video was short, simple and easy to understand thank u so much

[cdpalmo]

you're my favorite teacher ever, helped me with maths last year and now with chem. youre a life savior prof!!!!

[tylerjohnston]

Great video! Super clear and precise with no wasted time. Much more efficient and easier to keep engaged than those videos that write everything out. Thanks

[thegoose]

should state what state they are in (l), (g), (aq) or instance, NH3 are you talking about the (g) or (aq). Im assuming gas only because of the value you have chosen.

[oratilemoagi]

Thank you so much Dave for your videos they really helped a lot, I wrote my physics exam today and your intro song " He knows a lot about the science stuff, Professor Dave Explains" was in my head the entire time, lol and i think i nailed it, and now I'm studying for my chemistry exam 😁

[Real_Entertainment]

Dear Prof Dave, your podcasts including this one on Hess' Law are great. You have explained the chemical reactions so well. You are great and thanks for making Chemistry a lot more easier. Continue to do the great works with your podcasts.

[Roadways]

U have made this topic very easy in just about 5 min
Super work👍👍👍👍

[joebertcabalquinto]

Prof. Your video is very helpful even if it some is an unknown topic for me but when you explain it is understandable.

[ROKZILLA]

Thank you professor dave you are a blessing to all students and learners 🙏

[gavinrobitaille]

When I say this I speak for the entirety of my senior AP chemistry class, you are a god damned national treasure

[johnmerginio]

i don't understand how/why did you cancel the 2O2 and the O2 in the first example, I can't get my head around it