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+Sara Gates I think its good to bring out topics the way Hank does, because lets say someone is not too into science and they see it as a shady and peculiar topic. Hank introduces topics with some very good and hooking tone that drives readers into the video. However he has a tendency to speak extremely fast, which shows his high prowess in the English Language. However still, Hank is an excellent role model on how he approaches topics in chemistry, and biology.
I normally do not leave comments on youtube. However, you guys have helped me in everything from history to chemistry. You make things so clear, concise, and in a way that makes me pay attention. Thank you and keep up the good work.
And once again Crash Course saves my life with a video telling me exactly what to do and how to do it the day before a very important test. Than you Crash Course, thank you.
So i have an enthalpy quiz tomorrow.. thought process rn: thank you hank thank you hanks mom for making hank thank you hanks dad for making hank thanks god for making hanks family so hank will appear
For the specific heat capacity portion of the video, I just want to point out that the unit 's' signifies VOLUMETRIC heat capacity (also called volume-specific heat capacity). Volumetric heat capacity is measured per unit volume, whereas specific heat capacity (usually used for solids and denoted by the symbol 'c') is per unit mass.
i love this guy I've looked so long with someone with understanding of chemistry and can explain it throughly not just read the definition out of a book
This is wonderful. Sadly, by not fault of your own it came out after my chemistry exam. Yeah, the one where I panicked, messed up all my enthalpy and now have permanently f***ed up my A Levels. But thank you - hopefully you can save some other poor soul :)
I'm in first-year university chemistry, people get in trouble for stirring with the thermometer, half of them are mercury, mercury spills are very bad. Or if they're alcohol, they're expensive to replace. Though in Chem 11, my group did break an alcohol thermometer by using it to stir.
For most of the scientific community, specific heat capacity is represented by a lower case c, indicating the heat capacity per gram. A capital C is used for molar heat capacity, with either a P or V subscript for gases, if the calorimetry is done under constant P or constant V conditions. (BTW, Using c makes the heat equation q=mcAT look a lot like the name of a dreaded medical school entrance test, which is easier to remember than your smAT)
+somepeoplearewild He, in a Vlogbrothers Video, stated that he cuts out the breaths he takes because they take up .5 of a second and wastes time. XD Its efficient, its cool, just like Hank. XD
In my school, the difference between physics and chemistry was VERY clear. Chemistry deals with chemical phenomenons, physics with physical phenomenon. Chemical phenomenon are phenomenons where chemical composition changed, so substances necessarily must mix together. ALL ELSE: physics. So to me, A LOT of crash course chemistry videos were simply crash course physics videos. I'm not complaining, I'm just amazed you keep treating the diff between physics and chemistry as a matter of opinion.
I've found that reinforces my memory. When was in AP History last year, we would read a chapter in the book and then learn the previous chapter in class. That way, when we got around to discussing it, it was simultaneously cementing the knowledge in our brain and teaching us new materials.
thank you for this video, I am watching to help my son in his chemistry class and who are all of these people with their infantile negative comments? The should be thankful.
we did calorimetry in year 7 (though not half as advanced) we burnt monster munch and everyones thermometers exploded in the water we were heating. there were loads of pretty colours like purple and green and everyone wanted theirs to explode too, so as you can probably guess our results weren't great ;)
When I was in high school, I was a chemistry lab aide. In the first month, I had to make 1M HCl from from 12M stock HCl. My teacher didn't inform me I was supposed to work in the fume hood to do this. My nose was hurting for a week!
As soon as Hank held up the two bottles next to each other, I was like: D8 Oh crap, he's gonna do it! Afterwards: Wow, that was actually pretty anticlimactic.
One problem with the calculation is that you used the standard enthalpies of the covalent species (HCl, NaOH) instead of the standard enthalpies of the ionic, solvated species. Since strong acids and bases dissociate completely, the net ionic equation becomes important. The enthalpy of 0.100 mol of the reaction of OH- and H+ going to H2O is actually -5.73 kJ so you're not really that far off, but it could have been a bigger issue in other contexts where solubility becomes important.
I did this exact lab a couple of days ago in class. Yes, we used our thermometers as stirring rods. We did get different numbers from Hank's project but it was probably cause we used half the amount of HCl and NaOH
get this man a lab bench!! I love the awesome set that Hank is filming on, but I think Hank would be safer and could do cooler experiments if he had proper lab bench
I gotta say...... You are awesome! You are the one chemist in the entire world i can RELATE to. I love how you sneak in little Easter eggs into the episodes like wibbly-wobbly timey-wimey, David Tennant, Carl Segan, and Live long and prosper. You are like my equal in terms of geekiness.
True. Didn't make a video out of them and have an editor and a producer and a 100,000+ fan base, however. Seems significant. Students will be attempting to reinforce learning or discover new ways of thinking using these videos.
Yeah, the symbol I've always seen for specific heat is c. Once you play around with symbols for a while you just see them as symbols and don't care if it stands for something or not.
My teacher uses c for specific heat and C for heat capacity. Most of the problem comes from having to deal with the math language instead of plain english. It is like programming computer level instead of using an interface. Or Python vs a low end computer language.
yes, that was what I was trying to say but less lengthy. It is also worth noting that H+, or hydrogen ions can also contain nuetrons which is why I really don't like saying exchanging protons. I think it is much simpler and leaves less room for confusion if you say hydrogen nucleus or hydrogen ions.
I have physics exam tomorrow and this saved me . And HOW IS THIS PHYSICAL CHEMISTRY?! Makes zero sense for me but ok and thank you very much this is a life saver
I proctored for the chemistry department as a junior in high school and diluting concentrated stock acid down to 1M for lab use was a regular duty for me. Occasional I'd only make a quart of dilute but most of the time it was multiple gallon batches.
Yes. 2H20 equilibrium reaction H30+ + HO-. The protons can go back to where they started or go to another molecule. Google doesn't know the difference between arrows and HTML tags.
So, I know this is just a brief synopsis of calorimetry, but you could have mentioned more closely how calorimeter constants are found. I know that you said that some heat is lost to the surroundings, but you could have spent ~20 more seconds explaining that, even with improvised calorimeters, you can get relatively precise measurements. Just a thought.
Great video, as usual. On the subject of possible causes of inaccuracies between experimental data and theoretical data - surely the accuracy and precision you were able to measure the temperature was a significant factor as well?
They were exchanging H+ ions which ARE, strictly speaking, protons, but are the entirety of their own nucleus, and thus never contended with the strong force. The OH- ions that result from the spontaneous proton donation (water is a weak acid) and H30+ ions from the reaction of H20 and H+ (water is also a weak proton acceptor, and as such a weak base) form a small but detectable portion of water at any given time, although the H+ ions are accepted by OH or H2O too quickly to be detected.
yeah I was wondering about that too, his measuremed value was higher than his theoratical value, which is kinda weird because that would mean that something else must have warmed up the thermometer also.
Poor insulation (thus not accounting for part of the reaction's heat) would have reduce the magnitude of the calorimetric value (making it more similar to that calculated from enthalpy of formation)... So it is not a proper explanation for the discrepancies between the methods. Anyway thank you for such good work
@@krishnanarramneni587 By that I meant that a one-degree change in Celsius is the same as a one-degree change in Kelvin. Since the formula asks for simply the change in temperature, it doesn't matter if you use Kelvin or Celsius. Hope that clears it up.
Hank I thought you should know that my college chemistry lab instructor actually sent us to this video so we could be ready for a calorimetry lab. I'm amused.
I learned it as DeltaH=nCpDeltaT which is basically the same thing, n being the number of moles and Cp being the heat capacity at constant pressure (Cv+R)...It might be helpful if Hank adds this in though as another way we might have seen it.
Great video, as usual. Not to pick holes, but rather to warn against reinforcing a common misconception: @6:47 when talking about breaking and forming hydrogen bonds the animation shows the molecules of water breaking apart (breaking the O-H covalent bond), this is NOT a hydrogen bond. A hydrogen bond is NOT a covalent bond to hydrogen, but a specific type of INTERMOLECULAR bond/attraction/force. Take care over this difference, I've seen a lot of marks lost in exams due to this!
Oh - and before anyone tries to muddy the water, the fact that the H2O will form the equilibrium 2H2O H3O+ + OH- is a different matter (although obviously another way heat energy is 'used' rather than just increasing temperature) - my point is about the misconception over the term 'hydrogen bond'
Hydrogen bonds are bonds just like any other bond. They're of a lower strength than most covalent or ionic bonds but saying that they aren't bonds because our definition of molecules is based around covalent bonding is just pedantry. Just like there is no clear distinction between ionic and covalent bonds, the distinction between them and hydrogen bonds is purely a matter of degree.
