13.2 Calculations Involving Freezing Point Depression and Boiling Point Elevation

Struggling with Colligative Properties? Chad breaks down how to calculate Freezing Point Depression and Boiling Point Elevation!
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Happy Studying!

[@michelewills3252]

I wish you were my chem professor this semester, because mine sucks. I doubt I would have struggled so much if you were.

[@alexrosellverges8345]

Seriously, these are awesome lectures. Really clear and quick, thank you!

[@ChadsPrep]

Glad you're enjoying them Alex! If you plan to watch several of them I'd recommend downloading the outlines that are a companion to the videos from the free course on chadsprep.com. You'll find them helpful in note-taking.

[@alexrosellverges8345]

@@ChadsPrep oh i didn't know that, i'll check that out! You know i just wanted to congratulate you, bc apart from being a good teacher you seem like you love what you do, and thus make it fun. We need more chem teachers like you, i hated chem until i started following people like you on yb and now it is one of my favorite subjects!

[@ChadsPrep]

@@alexrosellverges8345 That's what i like to hear: you love learning chemistry and i love teaching chemistry...PERFECT!

[@evashweta1426]

U teach really perfect . It has helped me clear my doubts .😊

[@ChadsPrep]

Awesome! Best on your upcoming exam!

[@rheynellcortez7743]

You explained it very well. Thank you. ☺️

[@ChadsPrep]

You're welcome, Rheynell - thanks for saying so!

[@sandra5124]

THANK YOU! amazing video!

[@ChadsPrep]

You're welcome, sandra l - Thank you!

[@SAURABHKUMAR-dz5dt]

Thanks for vid . It really helped me 😊

[@ChadsPrep]

You're welcome, SK!

[@maricelalopez441]

OMG Mister Chad! I am a nontraditional student! SIr, you explain it well for me to understand! Thanks!

[@ChadsPrep]

Glad you found this lesson helpful Maricela! Best in your studies!

[@whenthethebeansstrikeback6728]

This literally helped me learn this and with Delta at the same time. Your students are lucky.

[@ChadsPrep]

Glad you found us - Happy Studying!

[@whenthethebeansstrikeback6728]

@@ChadsPrep thanks!

[@ChadsPrep]

👍👍👍

[@JakeYaks]

this video really makes it like duh anybody could do this when my professor turns it into rocket science

[@ChadsPrep]

Glad the video helped you, Shower!

[@cardiacmyxoma4073]

Hey Chad, I was wondering, for the transition metals, how do we determine the number of valence electrons? For example, in Vanadium, would it have 2 valence electrons (from 4s) or 5 valence electrons (from 4s + 3d)? Thanks in advance!

[@ChadsPrep]

Hey Genevieve! For the transition metals it is a little tricky. If the d orbitals are partially filled then you include both the s and d electrons. So in the case of vanadium we would have 5 valence electrons: [Ar] 4s^2 3d^3 The tricky part is that when the d orbitals are completely full then we no longer consider them valence but part of a filled core shell instead. So in the case of bromine it is readily known that like all the halogens it has 7 valence electrons: [Ar] 4s^2 3d^10 4p^5 So the valence electrons include the 4s and 4p electrons but not the 3d electrons in this case. Hope this helps!

[@macheltane9259]

nice video...for Calcium chloride if it dissociates to give ions do we put 3 or is it 2 on the (i) in the boiling point elevation formula

[@ChadsPrep]

i = 3 as you have 1 calcium ion and 2 chloride ions! Hope this helps! That is part of the reason CaCl2 is used for salting the roads.

[@tysken0251]

what is the freezing point depression law called?

[@swadha3]

All non-ionic factors have van't Hoff factor of 1?

[@stevencool9657]

Im a huge fan

[@ChadsPrep]

Glad to hear it!

[@danlao656]

In my classes the formula for the freezing point depression is Tf=Kf(m)(i). is that the same?

[@ChadsPrep]

The standard formula you'll find in any textbook omits the negative sign exactly as you present. Delta Tf = (i)(Kf)(m). But you should realize that freezing points go down and they expect you to realize that for freezing points you subtract the change from the normal freezing point. I simply decided to include the negative sign in the formula so that it is consistent with how we deal with Delta in any other context. When I teach this in person I make sure students are aware of this difference in the formula I provide and the one in their textbook. If I didn't mention this in the video my apologies but I'll be sure to do so next year when I produce an updated series. Hope this helps and happy studying!

[@badonkadonk6655]

@@ChadsPrep Hoping for the updated series!😄

[@michelewills3252]

How do I figure out boiling point with no information? All I have is Molarity and aqueous solution.

[@ChadsPrep]

You need the boiling point constant. On a homework question they may be expecting you to look it up, but on an exam it is something you are most likely to be given.

[@novakendrick]

goat

[@ChadsPrep]

You must mean 'Greatest of all Time', then: Thanks for saying so! If for some other reason, then: sheep / dog / cat / horse / cow / etc.....😁😁😁

[@stevencool9657]

My professor sucks i think this dude will be my tutor

[@ChadsPrep]

Welcome to the channel, S.C.!

[@matthewcostello2340]

im still confused are teacher gave us a workhseet and expects us to just know how to do this

[@ChadsPrep]

Hey Matthew - what are you struggling with?