Okay in this video today I’m going to show you how to do molar calculations and molar conversions and we’re gonna be showing you how to calculate from grams to moles and moles to grams. Now the first thing you have to remember when you calculate from grams to moles or moles to grams you have to use the

molar mass of the compound that you’re trying to convert. So here I wrote the generic form for the molar mass: 1 mole is equal to X number of grams. You need to remember that every compound has a different molar mass and before you start you actually have to calculate the molar mass. Now, before in the previous video I showed you how to calculate the molar mass and so for this video I’m just gonna write them down. Here for the first problem we have Magnesium Hydroxide; the molar mass of Magnesium Hydroxide is 1 mole equals 58.32 grams I recommend that when you do these calculations from grams to moles or moles to grams that you right down the molar mass in this form. 1 mole is equal to 58.32 grams because that is going to be our conversion factor. That is what we’re going to use to convert when we convert from grams to moles and moles to grams. Okay? So let’s go ahead and do a couple problems. The first thing I recommend people do is this: read the problem. How many moles are there in 30.10 grams of Magnesium Hydroxide? Now you need to think about what have you been given, and what are you trying to find? Obviously you’ve been given, and I put a little “G” here, 30.10 grams and you’re trying to find out how many moles. Okay I think it’s a good idea to

mark those down because the first thing you’re going to do is you’re going to write down what you have been given. So let’s write it down we have been given 30.10 grams. Just write that down; just follow the steps, basic steps write it down. Multiplication, your division line for your conversion factor. Now one thing you need to remember is you’ve been given grams, our molar mass is 1 mole in so many grams, if we have grams here in the top of this fraction so to speak, then we know that we’re automatically gonna put the grams in the bottom. We don’t really have to think about it

too much, we just put down 58.32 grams. And then the other for conversion factor goes on the top, that being 1 mole. You will see we want to find

out how many moles we have; we’ve been given grams our grams will cancel like this, we’re left with moles and if we multiple 30.10 by 1, divided by 58.32… we end up with 0.52 moles okay? That’s all there is to it it’s not that

complicated just try to follow the steps figure out what is you’re trying to find, what you’ve been given, write the thing down that you’ve been given, you’ve been given something in grams therefore the conversion factor part of your molar mass goes in the bottom for grams so you can cancel and then you’re left with moles. Alright? So that’s the first one now let’s do one where we convert back the other direction. Now this time we want to know what is the mass. So what what is the mass we’re trying to find, put a little “F” there for what we’re trying to find, we’ve been given some number of moles of Calcium Chloride Dihydrate so I’m gonna put down the given like that. Now once again I don’t think about it too much, just write down what I’ve been given like that. I was given 1.75 moles. I’m going to put down my division, my multiplication sign, my division bar,

and the molar mass of Calcium Chloride Dihydrate is that one mole is equal to 147.02 grams. That’s my conversion factor. That is what I’m going to use to convert from moles to grams. Now you’ll see this time I have moles over here. In this case I had grams, I put grams in the bottom. I have moles here therefore I’m just going to automatically know that 1 mole goes on the bottom. That is going to allow me to cancel, but I put my 147.02 grams, my molar mass, like that. That is the number of grams in 1 mole and then I end up with an answer that is 257.29 grams. You can see once again models cancel, I’m left with grams, I want to know what is the mass, that is my mass. With this problem I wanted to know how many moles, that’s my moles. Now you should notice that in each case you have your value over here that you’re given it’s either gonna be 1 mole divided by the molar mass or in this case because I’m given moles it’s the number of grams in 1 mole over 1 mole. So you can see I just switched these 2, here I had moles at the top and grams at the bottom In this case I had moles on the bottom and grams on the top. Okay, that’s all there is to it, follow those steps and I think you’ll be very successful. Thank you!

Thank you so much!! I have a chemistry test tomorrow!

Left handed….nice.

This video was really helpful! Really clear cut explanation. My chemistry teacher uses the same method (the multiplication and a division line thing) but I understood this much more. Thank you again!

when you got for the second one 1 mole=147.02 grams how did you get that answer?

what about significant figures?

this class was too helpful thanks

I finally understand!!! Thank you!!!

my man <3

Such a huge help. Thank you very much!!

lol awkward left hand

You are a great teacher man. 🙂

My teacher spent 3 days trying to teach this and still I didn't get it until I watched this video. BRAVO

i have a test tommorow on this where my teacher tried to make me memorize some formula to do this conversion, in your five minute video you TAUGHT me how to doit flawlesly and for that i thank you my good sir

omg thank you so much. I have a midterm tomorrow and I was struggling with this.

I have my midterm tomorrow and this video taught me more in 5mins than my teacher did all semester. Thank you so much man! This was really helpful

My teacher at school made me memorise a conversion formula and I had no idea what on earth I was doing until I saw your video which made gave my mind a clearer picture of what I was doing. So thank you for this

great stuff here thanks

where do you get the 58.32 from?

Great video. Very clear and easy to grasp.

Why is he not my professor?! -.-

Thank you, professor. Sometimes basic is what we need the most. This is an integral part for chemical engineers and chemistry

this was very helpful. thank you

thankn you so much. i have been missing a lot of school lately and couldnt grasp what my teacher was saying. you helped a lot.

Not all heroes wear capes..Thank you <3

I Found that very helpful. Thank you!

from where did you got 58.32g???

is that a mole on the table?? XD

I used the unitary method:

1 mol = 58.32g

? mol = 30.10g

Multiply diagonally, divide horizontally and I get 0.52 mol.

Is this okay?

Thank You! I have a final and you will really help me pass

Des Bleus!

Super helpful! Thanks a lot!

very helpful

You have saved my chemistry grade 😱 thank you! I have a test tuesday

What about avagadros number?

Perfectly Simple and well-explained yet detailed at the same time. I couldn't find anything better. Thank You for uploading this!

i learnt a lot through this video

THANKS A LOT

thank you and love your shirt

Thanks a lot!

thank you

Just saved me I have an exam tomarow

this shit is so complicated and its making me cry

The moler mass I got for CaCL2 X 2H2O was 131.02

Ca=40.08

Cl= 35.45 x 2

H= 1.01 x 4

O= 16

Mass = 131.02g

How did you get 147.02g??

Thank you very much for this video sir! Very informative!

Does anyone else feel the need to make fun of him but can't because he seems like such a nice guy?

Your videos have helped me so much! My CHEM teacher takes things to quickly sometimes and this really showed me how to do it properly

Please answer ASAP , How do you know what compound has what mole number? , for e.g for Mg (OH)2 how do u know its 1 mole = 58.32g ?

he kind of looks like Hank Hill, shouldn't you be selling propane instead of teaching?

bro this helped so much, so simple and well expained😭

My hero

I want to know the relationship between mass and volume of a gas at S.T.P soon .plz tell me.

doesn't 1 mole equal Avogadro's number or was that the molar mass of magnesium hydroxide?

Night before the final finally learned it

I have a chemistry final tomorrow and I didn't understand this at all….until now. It was a good explanation and easy to understand. Thank you!

THANK YOU!!!!!! This makes so much more sense!

legend

Only if every teacher taught the way you do the world would be a better place!!!! Teach so others can learn!!!!!!!!!!!!

Your video are too helpful for me! Thanks!

Thank you so much

Us Brits simply use the formula moles=mass/mr. Thats really it

YOU ARE A HERO

No. Thank you! That was very helpful. I was absent on the day of a test, so I had to take it while my teacher was talking about this. I had homework on it even though I didn't learn about it, so watching this video helped me finish it in no time. You make things very easy to understand. Good work!

Lol why don't chemistry professors know how to explain this without confusing the shit out of their class???!!! This made so much sense and it took just 5 minutes to explain to me!!! I wish my prof. would take notes.

You explained this better then my teacher did in 3 weeks. Thank you.

thank you for this video really helped with my chem final today or at least i hope it helps with the final

Bro, if mr.spence explains it like this. I swear my grade would be so up

Nice bro

You are too smart

BLESS YOU

I wish I had someone like you in high school

Man , I am glad that I subscribed to you ..

Thank you very helpful

Thanks

I've got the same shirt!

Thanx alot you're amazing

Very good teaching thank you

According to the significant figures rules, the answer should be 4 sig fig 0.5161 g Mg(OH)2 not 0.52

Dude but how did you get 58.32!!!

thank you so much for this!

thanks sir

How to convert 0.2 gram of moles of H2SO4 in grams

Ty sir

Why aren't you my chem professor in real life 🙁 ?!

Awesome you are great

Do significant figures not matter in these problems?

You're so much better than my chemistry teacher.

im confused on where he got the number 147.02 g ??

Thank you so much step by step science!! Very helpful. Despite my friends and teacher explaining dimensional analysis many times, I just didn't get it. But you thoroughly explained it. I really appreciate it!

Thank you, thank you!!!!!

Omg thank you very much, I didn’t understand anything until I watched this video, thank you

What a hottie

im just dumb and dont do work so i gotta look this up Real quick

I'm a left hander too 😊

thank you so much!

THANK YOU FOR SAVING MY GRADE. i did not understand this at ALL until i watched this.

What's that pola dotted thing in the middle?

how did you get 140 sumthing you feel? Suu whoop for the 1 time, fuk 12

Thanks a lot

Mole is equal to mass/RFM. Thank you sir for your explanation.

Adds: "The videos from 2012 wont help"

The add from 2012; "Hold my marker..!"

thank you so much this helped me a ton 🙂