Another mass composition problem

[goldensilverstar]

Stop making everything fuckin 100grams

[TwickenStep]

@goldensilverstar its still quiet easy even if you didnt use 100 grams. for example if the total mass of the mixture was 75.3, to find the mass of H O and S you just have to divide 75.3 by 100 then times by the percentage of the substance. eg, with sulfur it would be. 75.3 / 100 x 32.65 = 24.58 g. then you can do it with the O and H and see that all 3 values add up to 75.3. after that you just follow the rest of the instructions on this great video to figure out the empirical f

[TTRIPLEH]

@goldensilverstar you fool. the percents for every mass composition problem would add up to 100. so the only thing you CAN make it is 100 grams.

[Rind0Man]

@goldensilverstar Why would you use another number for other than 100g? Since the percentage of X number of elements should add to 100 anyway, there is really no need to differ from 100g. No need to be rude, question before you demand something.

[willyb1989]

YOU ARE MY SAVIOR!! learning what my shitty gen. chem. teacher couldnt teach the class all damn semester...forever indebted!

[BLACKNewSense]

wow... why go to the university?

[fivestargal1]

its nuclei lol; but anyway thank you SO much my chem teacher is bad at explaining, and your videos have saved my butt

[AhAhAhCHOO]

I think a light bulb just clicked. Honestly.

[moohendischi]

We should pay our tuition to you instead of our horrible profs!!!

[Shuffle2dMax]

1 person is from Port Sulfur hahaha

[rafaeldelaflor]

well that is true while I was a plumber. most of the time

[Fablefiend]

...most of the time?

[farhanhani]

yes, but you must do your part as well do study from your side

[farhanhani]

yes, but you must do your part as well do study from your side

[farhanhani]

yes i did.. but do study from your side he's really helpful

[AnimeWaterFall]

This is extremely helpful!! I actually understand it now!! :D

[kat33333]

But what if you didn't have 100g? What would you do then? How do you figure out the grams of atoms in that?

[Seranguyen]

@kat33333 It does matter because you'll need to know to find the # of moles of the element. If you have more than 100g for example, 123gram in a bag, then this is what you need to do:

123g x 2.04%H (or .0204 ) = 2.51g to get the total grams of H in the composition.

Same with O : 123g x 65.3% (or .653) = 80.32g

S: 123g x 32.65% (or .3265) = 40.16g

Now continue the problem by using these new numbers and each element's molar mass to convert grams to mol shown in video

[kat33333]

@Seranguyen  Thanks ^^ really helped alot :3

[Emberluver21]

You're my hero.

[msjayslover]

can i write the formula as SH2O4 or O4SH2? thank you so much for your videos!

[StAndAl0neCompl3x]

68 people have bad chemistry teachers like me. thank you!

[lurkern]

could someone please explain why it ends up with H:S:O, or H2SO4, instead of say, O4H2S or SH2O4? this feels the most intuitive to me

[xeuorux]

@lurkern It doesnt realy matter how you order it, but Sal wanted to order it the normal way that scientists do for Sulfuric Acid.

[TwickenStep]

@lurkern im pretty sure its because you always put a metals or hydrogen (not technically a metal) in front of all non metals and radicals. in this case you have hydrogen sulfate. (sulfuric acid) hydrogen goes before sulfate. and sulfate itself (SO4) i think they write the sulfur before the oxygen because there is less of it. i belive hydrogen can end up anywhere from first to last depending on what types of bonds its using. but please dont take my word for this. this is off my head.

[Rind0Man]

@lurkern There is a order system called the Hill System which states that Carbon and Hydrogen are written first. If there is no carbon then you write it alphabetically. But since this is for Sulfuric acid, it is an exception to the Hill system. H2SO4 is an Ternary acid (pretty much anything that doesn't have "hydro" as a prefix and ends with "ic" - like Sulfuric) will always start with Hydrogen and end with Oxygen.

Correct me if I'm wrong, anyone, but I think that's right.

[reeqho]

thank u sooo much for doing these problems step by step.. it sure does clear things up 4me

[Denseworldproduction]

4:15 1 mule hahaha X'D

[ppatbmw]

i paused the video at the very beginning when you only had the percentages listed. then i did all the work to find the empirical formula and i did all the steps and i got the right answer!!!...thank you so muchhh for being such a great teacher!

[lurkern]

@ppatbmw so did i and i completely agree with you. as do we all i dare say on behalf of the invisible crowd not bothering to comment =)

[amandazheng]

2.04+65.3+32.65=99.99

i think there must be a little mistake

anyway i like your "classes" very much

thanks

[jbeddiejb]

H2SO4, before watching up to 2 minutes.

[mcgarry11]

Do you always assume that there is 100g if not given the amount?

[Flush333]

@mcgarry11

Because it's a good number to work with.

[tomasiscool]

@mcgarry11 It's useful to assume 100g, and then once the empirical formula (or the ratio of elements to one another) is found, then that ratio can be reapplied to any given amount. In this particular example, if a given amount of 500 were given, then once having obtained the empirical formula through assuming 100g, Sal could have reapplied that formula to 500g.

[Welcome2DaCapital]

thank god for u guys!!!

[geordievb]

praise for all the great help

[juanarruti]

u sir........ i salute!

[farhanhani]

u sir...are a genius i m gonna nail the test next week inshallah

[Luigi84289]

@farhanhani How did you do?

[Jtking3000]

sulphuric acid is the thing you would want least poured on you.....most of the time

[megaelliott]

Lol, at what time would anyone want to pour sulphuric acid on themselves?

[eckosama]

sometimes it feels good. jk

[lurkern]

@Jtking3000 haha, is it even possible not to love this guy?

[aznlalaland]

i remember this. these were fun to do!