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

Dihydrogen monoxide (better known as water) is the key to nearly everything. It falls from the sky, makes up 60% of our bodies, and just about every chemical process related to life takes place with it or in it. Without it, none of the chemical reactions that keep us alive would happen - none of the reactions that sustain any life form on earth would happen - and the majority of inorganic chemical reactions that shape the surface of the earth would not happen either. Every one of us uses water for all kinds of chemistry every day - our body chemistry, our food chemistry, and our laundry chemistry all take place in water.

In today's Crash Course Chemistry, we use Hank's actual dirty laundry (ew) to learn about some of the properties of water that make it so special - its polarity and dielectric property; how electrolytes can be used to classify solutions; and we discover how to calculate a solution's molarity as well as how to dilute a solution using the dilution equation.

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

Table of Contents
Polarity 02:40
Dielectric Property 04:13
Electrolytes 04:29
Molarity 08:46
Dilution 10:56

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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! 

[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! :)

[Ansa]

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

[nightmaresleuth]

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

[xeonsignal]

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

[fahffythraine]

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!

[sabinegray]

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

[calebfisher]

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.  

[evanknowles]

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

[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

[thehoodedteddy]

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

[duketravers]

Tea is my aqueous solution to everything

[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 picky aren't

I do, never-the-less, love your chemistry videos.  I use them in my classes quite a lot.  Keep up the good work!

[Identified_Idiot]

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 .

[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...

[emilypond]

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).

[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.

[Kraized]

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

[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 <3

[lthompson]

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!