Ideal Gas Problems: Crash Course Chemistry #13

We don't live in a perfect world, and neither do gases - it would be great if their particles always fulfilled the assumptions of the ideal gas law, and we could use PV=nRT to get the right answer every time. Unfortunately, the ideal gas law (like our culture) has unrealistic expectations when it comes to size and attraction: it assumes that particles do not have size at all and that they never attract each other. So the ideal gas "law" often becomes little more than the ideal gas estimate when it comes to what gases do naturally. But it's a close enough estimate in enough situations that it's very valuable to know. In this episode, Hank goes through a bunch of calculations according to the ideal gas law so you can get familiar with it.

Pssst... we made flashcards to help you review the content in this episode! Find them on the free Crash Course App!

Table of Contents
Large Size + Attraction to Others 3:36
Mendeleev to the Rescue 2:30
The Hindenburg Disaster 6:19
Helium vs. Hydrogen 7:33
Making Fire with Cotton and Your Fist 10:15

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[crashcourse]

Pssst... we made flashcards to help you review the content in this episode! Find them on the free Crash Course App! 

[shadow]

"... the ideal gas law, much like our culture, has really unrealistic expectations when it comes to size and attraction." Nice.

[scorpiaflueman]

I always write Avogadro as Avocado in my Chem notes,

[jsherer]

At 6:05, I did the calculations and got 22.414007031828275. And you're right Hank, it was boring. I also did the calculations for the Hindenburg using ATM instead of 100 kPa and got 9, 199, 570.179161146 moles of hydrogen gas, or 9.2 x 10^6 mol H2. If I get enough thumbs up, I'll find a more exact measurement by using a better estimate for the temperature on that date.

[poonamjagtapfc]

I hope David comes here and says " I know you exist Hank"

[iNthGineer]

To all students watching this: In the workplace, unless you're shooting a rocket or operating a particle accelerator, the Ideal gas law is correct 99.9% of the time.

[JustMeZeed]

Hank says: "The Ideal Gas Law often becomes little more than the Ideal Gas Estimate when it comes to what gases do naturally."

My interpretation of this:

Perfect world: "Ideal Gas Law"
The real world: "Ideal Gas Flaw"

[skippy]

David Tennant must know you exist Hank. You're as internet famous as he is.

[EmergencyTemporalShift]

It would be so cool if David Tennant commented on this video.

[ZeroKage]

"and attraction, so far that's never gone away" Well Hank, you can blame that on all your damn charisma lol

[hellohope]

This taught me more in 11 minutes than my chemistry teacher has taught me in 3 months..

[aqeel]

I would just like to take this moment to thank Hank Green for helping me pass my 11th grade chemistry class.

[FroMaestro]

This was your best video yet, IMO. The inclusion of calculations (which I was compelled to double-check) made learning actually happen. I'd suggest including more calculations wherever possible b/c it'd take these videos to the next level of utility. Earning you praise beyond the ranks of the numerous 'my teacher sucks, but you're so amazing' comments that I believe less and less each day.

[WaldyrImbroisi]

Man, these videos are just amazing. The amount of content expressed in ten minutes is formidable. I think it is the most brilliant material available for learning Chemistry.
I graduated in Literature/Linguistics and have the bulk of my readings in Human Sciences / Arts, and, even so, I'm learning like hell. It's absolutely didactic. Thanks for this amazing work and congratulations. I'll keep following until video 46 and over :)

[Archiegirl]

These videos are great! I'm Biology/ Pre-Med and they help me so much with class! Is there any chance you could do a Crash Course in Organic Chemistry? That would be awesome.

[melon]

about an hour ago i was having an existential crisis over if I chose the right major because I suck at chemistry. this video helped me understand gas equations a bit more and subside the existential dread at least temporarily, thank you crash course <3

[RosaSteltenpool]

The english subtitles are so messed up: '100 kilopascal' gets written down as '100 kill about scouts'

[Mieraz]

"yes i'm looking at you robert BOYLE" xDD  

[danielvanhorne]

That moment when your teacher tells you to watch this video, instead of actually teaching you...

[lucasstraub]

I started CourseCourse preferring john, after this 13 episodes I'm team Hank all the way.
But as the old monk said "why compare?"