Water & Solutions - for Dirty Laundry: Crash Course Chemistry #7

[@crashcourse]

Pssst... we made flashcards to help you review the content in this episode! Find them on the free Crash Course App! Download it here for Apple Devices: apple.co/3d4eyZo Download it here for Android Devices: bit.ly/2SrDulJ

[@Ansa42]

"I named my first cat ion." Took me a full 30 secs to finally facepalm.

[@エコー-n6g]

8Ansa hello from 2020

[@Liamhvet]

Hydron

[@leo-hao]

█▀▀   ▄▀█   ▀█▀       █   █▀█   █▄░█ █▄▄   █▀█   ░█░       █   █▄█   █░▀█

[@handyheart]

Our chemistry teacher taught us a great way to remember the difference between Solutes, Solvents and Solutions. 'Solute is what you put; Solvent is where it went; and Solution is what you're producing' Hope that helped anybody! :)

[@sabinegray1450]

So what I'm hearing is, I don't need to buy energy drinks, I just need to dissolve some salt in water?

[@palacsintakat]

that basically all energy drinks are. water, dye, flavor, and salt.

[@hedgehog3180]

Energy drinks usually have caffine in them. They're basically coffee soda.

[@palacsintakat]

hedgehog3180 Caffeine doesn't provide energy though. It blocks receptors that make you tired. The energy part is just a placebo

[@madeleinet8937]

Pickle juice (AKA vinegar) is a great hydrator. Better than gatorade because you're not taking in massive doses of sugar at the same time.

[@jessicaolson490]

Energy drinks are caffeinated, if you meant Gatorade then ya, add sugar salt and potassium salt. Best to just drink water though.

[@evanknowles4780]

"it's good a killing things and that's why we use it in swimming pools"

[@edver6786]

Evan Knowles lmao, why didnt i see this 3 years ago

[@Zer0_Flowers]

Evan Knowles well, I should stop going to the pool then shouldn’t I

[@エコー-n6g]

Population control and hello from 2020

[@aksharaa5376]

yet another way to die in a pool. whoopee.

[@rxmuslxpin8136]

u.u Time to go to the pool then

[@emilypond2735]

Without crashcourse I would have lost my mind by now. I'm a history and language nerd, so chemistry is my archenemy. Because of this video I now longer am panicking about my next test, and so I thank everyone who works on these videos for helping me and my lab group not only get through high school but move on to hopefully be a teacher myself (though of course not a teacher of chemistry).

[@xeonsignal2429]

LOL 'I named my first cat ion.' Im done XD

[@user-tv3mc5tr9b]

i have a cats named nuetron, proton, electron, and ion. if i ever get twin cats there names will be solute and solvent

[@rohankalra4712]

cation lol

[@sstares1740]

even funnier when you know that ion in romanian is an actual name

[@favourak5144]

Are you paw-sitive about that

[@shubrotodas1154]

@@favourak5144 i gus' so.

[@nightmaresleuth237]

I work in a hospital, we use hydrogen peroxide to clean particularly stubborn instruments where the blood just won't get out. It's fun to watch it bubble like mad (oxidizing reaction from interacting with catalase). Also good at removing stains on plastic parts from surgical prep solutions

[@fahffythraine9995]

I would really like to thank you for Crash Course Chemistry, it is really helping me through high school, I really enjoy science, but chemistry is really hard for me to understand, because its makeup is so small and how it works in such a big way... it just really hurts my head sometimes, and thanks to you, I can actually understand it. All of the Crash Course playlists are amazing, thank you Hank, and John Green both for making these Crash Course videos!

[@zoaffius]

hey bro, did you ever pass high school

[@bipedal-ape-man]

It's not 0.24 liters of H202, it's 0,43 liters . Spent like an hour trying to figure out how to get 0,24 liters .

[@sometimelordything]

Oh thank god other people noticed this, I thought I had suddenly forgotten the rules of algebra or something

[@lamebrainsimran4217]

cannibis sativa I think you are right

[@peudroid]

Yes, 430ml, IF you accept that you need only 0,01 molar solution to clean and not dissolve shirts. Because Hank don't show where he got the molar solution 2.

[@Leroyawesome]

THANK YOU

[@adamperalta187]

thanks

[@hanneliseirrah4755]

Molarity and molality? Oh my God, No...........

[@Ptaku93]

+Hanneli Seirrah lal

[@AlbinosaurusR3X]

+Hanneli Seirrah ikr

[@gnuPirate]

+Hanneli Seirrah yeah.... It's equally as fun to remember as the difference between "Mitosis" and "Myosis". Apparently the people who decide this stuff can't make the frigging words for the differences more distinct than the difference between a vowel-sound and a consonant sound >:( What would be wrong with "SexSplit" and "BodySplit" or something clear like that?

[@nh-a6713]

+SixSixSix scientists like to sound clever

[@queensaharaice7376]

lol ikr? well that's science 4 u... were just gonna have 2 learn 2 live with it... (damn scientists...)

[@calebfisher3348]

At 9:50, molality=moles of solute/Kg of solution. Instead, it should be: molality=moles of solute/Kg of solvent. The mass of the solution and the mass of the solvent are two very different values.

[@NullHyp]

12:20 is WRONG!!! V1=(M2xV2)/M1 =(0.01x38)/0.88 =0.43L Not 0.24L What's more is that 0.24L=240mL not 250ml

[@bng_ultra646]

😳

[@natalyabarton2205]

Thank god. I was following along and thought I'd really screwed up my maths

[@エコー-n6g]

🥰

[@tb2748]

Jesus, there are so many errors in these videos they have made. Correction annotations have been removed too.

[@sudeepjoseph69]

@@tb2748 You are a believer in Jesus? When did you repent of your sins? I am a newly convert as well.

[@duketravers9706]

Tea is my aqueous solution to everything

[@emilypaajanen1417]

+Duke Travers same

[@Zer0_Flowers]

Duke Travers you must be a true Englishman

[@diyapudota]

Yes lad i bet ye haven't had a good bit of sugar in it

[@kayadahlke4218]

Hey! You! Stop scrolling! Get back to learning!

[@novalie1151]

"You'll remember, I hope." Come on Hank, have more faith. What were we talking about again?

[@jackiewang8411]

He's like the Bill Nye of youtube. And for teenagers.

[@sudeepjoseph69]

Okay jackie, stay away from corona

[@Marinealver]

Damn there have been a lot of scientists shunned and ridiculed by their peers and seniors. Does this stuff still happen today?

[@MontySlython]

***** Of course it does, just a lot less now, well mostly (there was that one scientist that helped land a probe on an asteroid and he was ridiculed and attacked by feminists because he wore a shirt with hot chicks on it)

[@Molly-td5fx]

Nate G he was criticized for that shirt because it was highly inappropriate and in pretty much any workplace he'd be major trouble with his boss, or even fired. when discussing something highly important in your work environment, you'd probably want to dress very nicely and not wear a shirt with half naked women on it that distracts your audience from the hard work you have done.

[@MontySlython]

Molly Name Wow and to go so far as to completely destroy one of the greatest achievements in this guy's life so far just because he has a casual shirt on? Besides being fired for wearing an "inappropriate" shirt on the wrong day when he had just landed a fucking probe on an asteroid would be really stupid to begin with. Also that wasn't just criticism that was a public shaming that completely over clocked this amazing achievement and made it seem like it doesn't matter because *gasp* he's wearing a shirt he likes but somehow offends someone else.

[@Molly-td5fx]

Nate G literally tell me what job you wouldn't be fired or at least reprimanded for wearing a shirt as inappropriate as that to present such great discoveries to a worldwide audience

[@MontySlython]

Molly Name Actually I remember reading that his colleagues didn't give two shits what he was wearing they saw him in that shirt and did not reprimand him or get mad at him, please if they cared about what he was wearing they would have put another scientist to do the press conference or whatever and no he did not get reprimanded the only negative backlash (from what I could remember) was from a bunch of butthurt women and misguided feminists.

[@gaulearnedimp]

Hi there! Huge fan of Crash Course, and interested in learning Chemistry. I eat CC Psychology episodes like candy. Digest CC Mythology for fun. CC Philosophy is one of my guilty pleasures. You guys do a GREAT job. Buuut... I'm finding it hard to understand CC Chemistry. It moves too quickly, and doesn't include enough labeling in the visual examples to follow what everything is, when showing processes or patterns. A whole episode on ions wouldn't be a bad idea, for an idea of how pacing could be easier to follow. Again, huge fan! I would love to see a CC Chemistry 2.0 Thank you for all you do

[@Kraized]

Whoa, why is Wall-E with mr. Faraday 5:50

[@headybrew]

+Kraized I was wondering that myself.

[@saeedbaig4249]

Just out of curiosity, is any1 here just because they genuinely enjoy learning about chemistry in their free time and aren't studying for school? Like, their other subjects I can understand. Physics is weirdly wonderful in that it has lots of counter-intuitive things like general relativity and quantum mechanics. Philosophy (or, to b more specific, God) is always an interesting topic of conversation. So is politics (which's also important, if u want some idea of how 2 vote) and economics is a somewhat controversial (yet all the more interesting because of it) subject to be educated about (especially since it sort of links back to politics), which's y I keep up 2 date on those videos of theirs (still waiting for that modern physics tho!) However... I have never met any1 hu is just interested in chemistry and wud go out of zer way 2 learn it. At least, not as much as those other subjects I just mentioned.

[@Funymoney010]

same here I'm just watching because I find it interesting and like learning and getting smarter

[@saeedbaig4249]

Alex Christensen 2 each their own I guess. Enjoy!

[@solarisgemrestoration]

I am! 😀

[@uhumanu6600]

its an intimidating subject, and unlike politics, philosophy, and economics, it's one that you can't really get deep into without experimenting and gaining first hand experience in a classroom or lab. You can talk with your friends all day about the meaning of life, but you can't really study chemical reactions just for fun, because for one, the equipment isn't readily available, and two, it takes a lot of studying just to be able to conceptualize what is really happening. Its an invisible science mostly, and people don't find what they can't easily understand or even experience to be very engaging . I think if more people really dedicated just a little bit of energy to see what chemistry can show us beyond just equation balancing and a periodic table, they would see how amazing the science really is. But you kinda have to go to school to get that basic and necessary understanding

[@adhdengineer]

I'm currently restraining myself from buying a set of lab glassware off ebay. loads of of the fun bits for 85 uk £. i've no idea what i'd do with it but i want it.

[@zerosixe]

No ones doing actual calculations.. the M1 is wronggg.. its .432 L or 432 mL.... Unless my calculator is broken, which i doubt. Im sorry Hank, your clothes will still be dirty after yo tea..

[@DAVASAURUSREX]

your calculator is not broken, you just switched the numbers when dividing (38/0.88 instead of 0.88/38) which works out to 43.18 and then multiplied by 0.01 to get your figure of 0.432L. The equation will work out if you divide the moles into the liters.

[@DAVASAURUSREX]

DAVASAURUSREX Also Sig Figs!

[@majawillumsen519]

I need a crash course to understand this crash course xD

[@brandonstout337]

This guy is HILARIOUS, still very smart and a great teacher! I'd buy this course

[@TheIsioisi]

+Brandon Stout Good thing it's for free huh

[@ceoofdrugs4968]

12:13 Sorry but the math didn't add up to me , when I tried to calculate it I got 0.431 (Am I wrong or something?) Can someone give me an answer

[@engerlandt]

As a pharmacist, %w/v is actually really useful. Allows us to work out how much drug there is in a volume of liquid which helps with dosing up little kids :p

[@ZBostOneR]

And you allways asume that is a percentage of ml in grams? I can't really get this

[@AlexIsAwesomez]

You might MIGHT have just helped me pass my GCSE Chemistry. Thank you.

[@petercook9780]

The chemistry seems good as far as I can tell, but the physics at 5.24 with the light bulb turning on makes me sad. No matter what is happening in the beaker, the circuit isn't completed in two ways so the light can't turn on . 1) Connect to both ends of the battery. 2) Connect to both the base and metal side of the light bulb.

[@mustang6172]

V1=(0.01 mol/L * 38 L) / 0.88 mol/L V1=0.38 mol/L / 0.88 mol/L V1=0.43181

[@angelaflierman]

I got the same. Is Hank's math off? That's the second time that happened in this series. WTF Hank, you might want to ask Santa for a new calculator.

[@BlingSco]

Yh, lol I got the same.

[@headybrew]

+Tirra Hargrow How do you round 430ml to 250ml? I think it's a plain ol' mistake.

[@EnglishRain]

Can you tell me where did he get the molarity of the diluted solution / M2? How did he calculate it to be 0.01?

[@stepheninator2]

he didn't calculate that, it was the desired molarity for a proper laundry solution

[@ahnafnouveau]

Molality is NOT moles of solute per kg of solution. It is moles of solute per kg of SOLVENT. Probably a silly mistake by mr. hank

[@pragyasahay2K]

+Ahnaf Islam Actually, he is right because we are talking about the stuff in a whole SOLUTION and NOT in just the solvent

[@Ismackaru]

+Pragya Sahay yeah but molality is moles of solute over kg of solvent. Period. U can't change that

[@djr5995]

+Pragya Sahay Molality is a property of a solution and is defined as the number of moles of solute per kilogram of solvent. Just do a simple search before you try and correct someone. Google -> Molality -> sorted. Easy :)

[@integral1191]

actually mr. hank was right

[@samuelralte7]

Molality can also be understood as ratio of solute to solvent, while molarity is the amount of solute in solution

[@tedderchemistry]

Ditto to caleb fisher's comment. Molality is moles of solute divided by kilograms of SOLVENT. Actually, for most solutions where we care about colligative properties (one of the main reasons for using molality) the results of the math come out almost the same but we chemistry teachers are soooooo picky aren't weeeee! I do, never-the-less, love your chemistry videos. I use them in my classes quite a lot. Keep up the good work!

[@reneemiller7102]

Favorite Chemistry teacher.

[@thehoodedteddy1335]

We need more people like hewell these days. There are so many things that could use cooler names

[@Zyamaman]

10:23 yeah, dude, measuring solutions in percentage might not make sense to chemists, but it's the way to go in medicine. We dispense drugs in doses, meaning we just need to know the mass of the drug we're giving - the solution it's in is often secondary. If we'd have to figure out dosage from a liquid's molarity' rather than percentage, a lot more people would die in hospitals...

[@DBates132]

Anyone else notice Faraday with Wall-E?

[@sacchrine_]

yea, can someone explain that to meeeeeeee?@_@

[@joshn2564]

I understand from the picture that Both Wall-E & Faraday are Geniuses who work with each other.

[@Charlie2531games]

1. They have Crash Course History and Literature. 2. I've seen those channels already, and they hardly ever mention it, at least not in the videos I've seen. 3. I've tried searching for calculus videos. Most of the ones I've watched say "and you can see the rest of the videos if you sign up for this course on our website and pay..." you get the idea.

[@MegaCraigh]

You guys need to stop being so DILUTIONAL. No? I'm joking.

[@declansmith6432]

delusional* 0_o

[@MegaCraigh]

Dilutional? As in dilute? As in to make a less concentrated solution?

[@MrSpyer]

I take chemistry, and i have learned more in this than form three weeks of work.

[@KWFit]

how'd he get the the final answer? im stuck when i get V1 = 0.43 L

[@annasenpai3674]

try to press the transcription button or use the caps to follow. if you press the pause button, read ahead the transcription and then unpause it and listen to him. it might help ;)

[@AlbinosaurusR3X]

I think Hank might be the next Bill Nye. =)

[@skelosgaming3312]

Bill Nye the science guy!

[@RandomPersonTime]

+skelos gaming BILL! BILL! BILL! BILL!

[@johnreyes2461]

Never ///:

[@TheSpecialJ11]

+AlbinosaurusR3X Sadly Crash Course doesn't allow for that same kind of silly charisma; it's better for more quick and dry humor to keep information flowing and get the concepts as deep as possible in a 10-15 minute video. Quick and dry humor doesn't usually work well with kids, but with late tweens, teens, and many adults.

[@TheSpecialJ11]

+AlbinosaurusR3X Sadly Crash Course doesn't allow for that same kind of silly charisma; it's better for more quick and dry humor to keep information flowing and get the concepts as deep as possible in a 10-15 minute video. Quick and dry humor doesn't usually work well with kids, but with late tweens, teens, and many adults.

[@anderstaylor6694]

12:01 "We need a zero point one molar solution". You forgot the second zero: should be "point zero one". Sry.

[@EnglishRain]

Can you please explain how did he find out M2? How did he get 0.01?? It is at the same timestamp that you quoted.

[@pedrobravo4404]

#makesockswhiteagain

[@yikesmcgee1283]

Pedro Ignacio Bravo Collado too close to home buddy. Can’t help but wanting to stop the white replacement

[@kathrayres]

A question that I've never been clear on: When the component ions of a compound (say sodium chloride) are dissolved in water, to they retain their "sodium chloride-ness" or do they display the properties of the component ions? In other words, is salt still actually salt when it dissolves?

[@ThePandaclash]

I love that there are are no spammers on crash course videos!

[@NotEveryoneEats]

We watched this in my Chemistry class today. :D

[@l8thompson]

I've been using these videos for my chem notes. It's makes way more sense than my textbook and my teacher, I just have to pause a lot; thanks #crashcoursechemistry!

[@SulisFidelis]

Because it's in a safe form, I think. Chlorine gas is in the form Cl2, but when it is dissolved it is separated into Cl1, which is possibly not as dangerous (I'm not sure, though, I only studied Chemistry until I was 15)

[@HamzahMC]

But is water wet?

[@ilikegaia]

In grade 5, our teacher told us to search up dihydrogen monoxide and read the articles, as a lesson on information gathering. It was described to be so treacherous, the cause of hundreds of deaths every year (they meant drowning) and a hazard that was easily accessible. We thought it was a terrifying thing and everyone got worked up....for water.

[@FraserSouris]

It is weird that on how many people were laughed at for being right. (e.g Wegener, and many of the people you mentioned in Chemistry)

[@sutfolsemaj]

Fraser Souris For each of these men who were laughed at when right, hundreds were laughed at and wrong.

[@vishvakseenichamy]

James Loftus Wise Words

[@otacon1024]

"All truth passes through three stages: First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as self-evident." - Arthur Schopenhauer

[@curiousmind5632]

dm^-3 is just another way of writing L^-1. They both describe the same volume of space.

[@sarahjohnston6072]

Oh my god I'm s happy we watched this in my science class and I was like yeasssss it's hank! And everyone was like, why is he talking so fast ? It was so awesome :D

[@hello12313211]

I absolutely love all of your crash course videos! I adore learning about science, but find it incredibly difficult to follow in class. These videos are perfect! Thank you!!!

[@katherinetheawesom]

If a molecule's(like salt's) solubility in water leads to dissociation between the molecule's cations and anions, then how is it still the same substance as before? Wouldn't that make it into a different thing all together? I mean, salt still tastes like salt when you dissolve it in water.

[@0olong]

Syne the Sage yup, our salt-tasting cells are sensors for simple anions like sodium ions (but not hydrogen ions, which are what our sour receptors sense).

[@wycka001]

I'm pretty sure that when non-ionic atoms or molecules (HCl for example) produce ions it is called ionization, not dissociation.

[@maruthgoyal1367]

How the hell did Hank know the values for M2 ?

[@Thejobla6]

Sort of - when you sit in the bath you will release ions into the water (eg through sweat) so the water will not stay pure

[@isidromaldonado5710]

bruh, thanks for making these. I have an awesome Chemistry professor but she skips a lot of material. These crash course videos really help me fill in the missing links.

[@cyekim1]

I had a dyslexic chem teacher, and he warned us that he made mistakes frequently, so when we did molarity and molality on the same day, I thought he was just really confused...

[@petera5146]

Pure water does conduct electricity due to the ionization/de-ionization cycle Hank :-) i.e. there are always a certain amount OH (Hydroxide) and OH3 (Hydronium) ions present, approx. (concentration) 1 x 10-7 M each respectively present in pH neutral water - hence pH7. Pure H2O (theoretical) would not conduct elec. I suppose, as it has no free electrons - but good luck finding that! As you say water is such a great solvent. Thanks for the great classes, awesome! (Personally I see water more as a fundamental force of nature anyway) ;-)

[@mrafaeljidi]

NA, Agreed. It was a huge discovery but why focus so much on the value so often? what do you really get out of 6.0221415*10^-23 other than the fact that it is a pretty large number. You don't really use it other than in calculating very specific things such as crystal structure from density or Faraday's constant or the ideal gas law constant. And as you can see the NA gets pushed aside by replacing constants R and F. What you do use all the time is the molecular weight of specific elements.

[@howtoguro]

Electrolytes, it's what plant's crave!

[@samuelawe8886]

idiocracy

[@Aleat6]

(Exactly my point!) Whichever Hank is using, and/or both.

[@heinsaar]

It's not 'molarity', it's 'morality'.

[@TrueTreeRadioNetwork]

I don't get it. He lost me after video number 3, electrons. Biology I get, but this...these numbers...completely indigestible.

[@DrReginaldFinleySr]

Phew! I thought it was just me.I swear I have dyscalculia. :-(

[@TrueTreeRadioNetwork]

wikiwikiwee Not as lazy as you were when the difference between your and you're was explained.

[@dasuberpanda]

TrueTreeRadio hoooly wow shots fired

[@nehatheturtle543]

+TrueTreeRadio SAVAGERY

[@nehatheturtle543]

wikiwikiwee chilllll its been a year lmao

[@ShadowZZZ]

according to chemists, alcohol is a solution :)

[@stefanieallworth3622]

It's a shame I need to reproduce all this stuff in german... makes everything just a little bit more difficult.... but luckily I have found that most therms just literally translate... THANKS SCIENCE!!!

[@mrthugamer7603]

Wait, but when H²O² breaks apart into H²O+O- Why does the O- take up electrons when it is negatively charged?

[@tronicdude6]

A solvent is USUALLY water but can also be a gas or a solid.

[@annieandersson9463]

I don't get the math at 11:54 together. I get this: 0.88 mol/L*V1=0.01 mol/L*38 L 0.88 mol/L*V1=0.38 mol 0.88 mol/L*V1/0.88 mol/L=0.38 mol/0.88 mol/L V1=0.43 L But he says 0.24 L? Can someone please explain?

[@NullHyp]

It is WRONG V1=(M2xV2)/M1 V1=(0.01x38)/0.88 = 0.43L

[@sen5295]

I thought I was becoming stupid

[@seanfarrell9297]

+NICHOLAS CHAMBERS V1 is the amount of solution that Hank will be adding to his laundry and is the variable that we are trying to solve for . If he poured in the whole bottle, it would be 1 liter. However this would be too much H2O2 for his purposes. He gave us 0.01mol/liter as the ideal dilution of H2O2 to whiten socks and we know he will have 38 liters of water in his tub. So now we just need to find how much hydrogen peroxide to add to that 38L in order to get down to the proper dilution of 0.01mol/liter...which is apparently 0.43 liter. Hope that helps!

[@danielcherry3748]

I've got the same answer, I have a feeling they messed up the math in this video??

[@marcusmajewsky9831]

thank you!

[@mjgc00]

Molality is actually the moles of solute/ kg of the SOLVENT. It is tricky and different. :)

[@ReplacedTea]

Dude, I tip my hat to you. You have a video for everything I have needed so far in chemistry. Thanks for the help buddy :)

[@ruchiktrivedi3059]

this taught me more than a week of school

[@danielmazzone7130]

The end of the video confused me a little. When you do the math to calculate initial volume it is: (M2*V2)/M1 = V1 which if you plug the numbers in is: (0.01*38)/0.88 = 0.43 mol/L. Somebody tell me where I went wrong.

[@lilkoo93]

I got the same answer, I don't understand!

[@jonasbertels861]

I don't think you're wrong, many people got the same answer: 431ml

[@aniketh_99]

Daniel Mazzone yeah it's actually right it's 0.431 litres I think it's cause Hank didn't have the capacity for it in his measure😂

[@PrettyyBoyyPatrick]

I thinn .43 is right that's what i kept getting on ny Nspire Cx Cas

[@Ravilrob]

Gotta love formulas in Chemistry. too easy

[@AdmiralRivers]

Your intro made me very thirsty.

[@MultiGoldenAce]

Molality formula is incorrect. Molality is moles of solute/kg of solvent (not solution).

[@mikeischangingplaces]

Also, % weight by volume is absolutely one of the most common ways of describing solutions in chemistry. If someone says "x% solution", they mean percent weight by volume. And lots and lots and lots of solutions are described that way

[@PartVIII]

Oxygen ion (O w/ 8 valence e) =/= Oxygen radical (O w/ 6 valence electrons) and it looks like a minus, not a dot. if it were a dot, it would also be incorrect.

[@youssefkashef7652]

Hank, thank you . This course gave me a better understanding of chemistry in fact, made me understand it

[@mrvalz1]

That is correct. Nice catch.

[@WLBFTWproductions]

I absolutely love how they do a background on some of the great discoveries of chemistry. I pretty much do this this stuff for a living and I have never learned who the Arrhenius is in the Arrhenius equation or Avogadro in Avogadro's constant until this show. Amazing.

[@robert_wigh]

Great video! Although, you advertised for both _Apple_ and _SciShow_...don’t know what I think about that. Just, kiddin’! :-) I have a _MacBook Air_ and I am also a subscriber of _SciShow_.

[@nivethasivakumar3740]

Make video on coordination compounds please!! Your videos really made me score more!!! I got a hundred marks more on my last exam which is actually for 720 . I got 500 due to your videos . Even the toppers get only300.

[@edgarmendieta91]

Hank you make math equations fun to watch.

[@daiziemaningding5640]

I’m so annoyed with the fact that Crash Course teaches me more than my actual Chemistry teacher 🙄🤦🏻‍♀️

[@NoniTinystorm]

in sci show can you explain how people who use many many tea bags in a making of tea and then drink a lot of that tea manage to damage their bones?

[@RajShah1]

I thought molality involved mass of SOLVENT, not solution?

[@rishisharma5035]

u are right

[@jessiccagirtman7456]

I'm so glad I'm not the only one who noticed that.

[@magma_chicken9993]

Hmm... if the bottle said '3% solution, volume per volume' instead of weight per volume, then with a quick calculation it would weigh 40g. 40g / 34.014g per mole = 1.18 moles. Molarity = 1.18 moles per litre of water. 1.18 mol/L x V1 = 0.01 mol/L x 38L. So V1 is about 320 millilitres. Someone, please check this! I haven't started learning this in school yet and I'm not sure if this is right...

[@andreavargas3961]

HEY, here is a mistake !! Molality is m= moles of a solute/ kg of a solvent , you may put a corection , you made me doubt for my exam , really like CrashCourse :D

[@emmagraceling]

Totally thought he would talk about surfactants and emulsifying agents.

[@redcartiers]

#bestchemistryteacherever

[@fatimamahmoud4261]

from now on I will call it dihydrogen monoxide because I love chemistry

[@KB24Nation24]

much appreciated if you could add text transcripts for your videos!

[@queensaharaice7376]

U mean captions?

[@benwhitcombe9880]

Do people actually get to watch Crash Course in classes at school? I find myself constantly holding out for the day when a science teacher plays us a Crash Course video.

[@davidfeng6120]

How in the world did Hank get 250mL?

[@headybrew]

+David Feng I've been trying to figure that out. My calculation comes out to 0.43 liters ( 430ml ). Am I doing it wrong?

[@michaelmacmanus]

+headybrew I'm getting .4318~ as well. Despite that, the main thing I'm going to have trouble reconciling after this lesson is the fact that I found useful KZbin comments.

[@headybrew]

+Michael Macmanus ha-ha. true.

[@poiewhfopiewhf]

+David Feng I got this too, but I realize that then the total volume would be 38 L + 430ml

[@historyoverviewtheoriginal]

“The Crash Course theme song is like the Soviet anthem of the nerdy percent of the world.” -Me

[@ShadowZZZ]

LOL, the dilution equation looks very similar to the conservation of momentum equation in physics! :D

[@infiniteach1390]

At 9:53, the formula of molality must be moles of solute / kg of "solvent", not solution.