Chem question, please help and explain!

[thefifthbeatle]

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In a sample of Al2(SO4)3, calculate how many ng are necessary to provide 1.00x10^20 atoms of oxygen. Assume all oxygen atoms are found in the compound Al2(SO4)3

Thanks!!!!!!!! I need an explanation big time!!!

 

[mh0000]

In a sample of Al2(SO4)3, calculate how many ng are necessary to provide 1.00x10^20 atoms of oxygen. Assume all oxygen atoms are found in the compound Al2(SO4)3

Thanks!!!!!!!! I need an explanation big time!!!

(1e20 atoms O)(1 mol O/6.02e23 atoms O)(1 mol Al2(SO4)3/12 mol O atoms in compound)(MW of Al2(SO4)3/1 mol Al2(SO4)3)(1e9 ng/1 g)

*too lazy to open a periodic table, so you will need to put in the molecular weight of the compound*

 

[rockclock]

In a sample of Al2(SO4)3, calculate how many ng are necessary to provide 1.00x10^20 atoms of oxygen. Assume all oxygen atoms are found in the compound Al2(SO4)3

Thanks!!!!!!!! I need an explanation big time!!!

Here's your set-up...too lazy to do the molar mass or final answer for you:

1.00e20 atoms O x (1 mol/6.022e23 atoms) x (1 mol Al2(SO4)3/12 mol O) x (?? g Al2(SO4)3/1 mol Al2(SO4)3) x (1e9 ng/1 g) = ?? ng Al2(SO4)3

 

[rockclock]

haha it's like looking into a goddamn mirror, mh

 

[thefifthbeatle]

Thank you very much!!!!!!!!!!!!!! One more please:

2NH4Cl + Na2CO3 -------> 2NH3 + CO2 + H2O + 2NaCl

What is the theoretical yield of NH3 assuming you started with 4.8kg NH4Cl and 4.8kg of Na2CO3

Also, in addition, if the actual yield is 1.4kg NH3, what is the percent yield? Was the reaction successful??


Thanks!!!!!!! I am helping a family member study my old DAT notes (Im a senior in Dschool) and I have totally blanked out on this stuff!!!!! I used to know this stuff inside and out 🙂

 

[thefifthbeatle]

Two last ones, and I'm out, I swear:

What are the types of intermolecular forces in the liquid state of

C2HBr

and

CH5N


Label with (can be more than one) dipole attractions, Hbonds, dipole-dipole interactions, dipole induced dipole and or london forces. EXPLAIN Please 🙂 Thanks again!!!!!!!!!!!!!!!!!!!!!!!

 

[rockclock]

Thank you very much!!!!!!!!!!!!!! One more please:

2NH4Cl + Na2CO3 -------> 2NH3 + CO2 + H2O + 2NaCl

What is the theoretical yield of NH3 assuming you started with 4.8kg NH4Cl and 4.8kg of Na2CO3

Also, in addition, if the actual yield is 1.4kg NH3, what is the percent yield? Was the reaction successful??


Thanks!!!!!!! I am helping a family member study my old DAT notes (Im a senior in Dschool) and I have totally blanked out on this stuff!!!!! I used to know this stuff inside and out 🙂

convert 4.8 kg NH4Cl > g NH4Cl > mol NH4Cl > mol NH3 > g NH3 > kg NH3
do the same for 4.8 kg Na2CO3
you'll get two answers for kg NH3, take the lesser of the two (that's how much you'll be able to produce until the limiting reagent runs out)

percent yield is just 1.4 kg NH3 divided by whatever kg NH3 you get as the answer in part 1.

 

[mh0000]

Thank you very much!!!!!!!!!!!!!! One more please:

2NH4Cl + Na2CO3 -------> 2NH3 + CO2 + H2O + 2NaCl

What is the theoretical yield of NH3 assuming you started with 4.8kg NH4Cl and 4.8kg of Na2CO3

Also, in addition, if the actual yield is 1.4kg NH3, what is the percent yield? Was the reaction successful??


Thanks!!!!!!! I am helping a family member study my old DAT notes (Im a senior in Dschool) and I have totally blanked out on this stuff!!!!! I used to know this stuff inside and out 🙂

lol, this explains your footer (class of 2012) that you must have just removed. I was thinking this person needs help if s/he can't stop thinking about the DAT 1 year from graduating d school

 

[rah08e]

convert 4.8 kg NH4Cl > g NH4Cl > mol NH4Cl > mol NH3 > g NH3 > kg NH3
do the same for 4.8 kg Na2CO3
you'll get two answers for kg NH3, take the lesser of the two (that's how much you'll be able to produce until the limiting reagent runs out)

percent yield is just 1.4 kg NH3 divided by whatever kg NH3 you get as the answer in part 1.

If anyone did this question I got 1.54 Kg from Na2CO3 and 1.53 Kg from NH4Cl so I did 1.4/1.53 .... I think thats right

 

[LetsGo2DSchool]

(Im a senior in Dschool) and I have totally blanked out on this stuff!!!!! I used to know this stuff inside and out 🙂

LOL, how did you get into dental school?

 

[thefifthbeatle]

LOL, how did you get into dental school?

Oh. I am supposed to remember every fact from undergraduate chemistry? Oh yeah I forgot. Dental school has no new facts to memorize whatsoever. Everyday in class we discuss %yield. Dental school isn't stressful, either. All we do is talk about college chemistry. General chemistry. We don't have national boards or regional boards to worry about. Or patients. Or deadlines. Or labwork. Or a full 8-5 class day. Just memorize your basic chemistry. You're right I am dumb. All they do is reinforce it all day and all night.

So how did I get into dental school? The exact opposite from what you're doing...because you can't get in.

 

[redkbro]

ahhh

 

[mh0000]

Oh. I am supposed to remember every fact from undergraduate chemistry? Oh yeah I forgot. Dental school has no new facts to memorize whatsoever. Everyday in class we discuss %yield. Dental school isn't stressful, either. All we do is talk about college chemistry. General chemistry. We don't have national boards or regional boards to worry about. Or patients. Or deadlines. Or labwork. Or a full 8-5 class day. Just memorize your basic chemistry. You're right I am dumb. All they do is reinforce it all day and all night.

So how did I get into dental school? The exact opposite from what you're doing...because you can't get in.

What!? You mean to tell me that you don't do percent yield in D school? 😛 Don't worry about the comment, I think it's cool that you are helping out your family member prep for the DATs. I'm just jealous that you're in your last year of D school 🙂

 

[mh0000]

haha it's like looking into a goddamn mirror, mh

<ComicalArrogance> You must be one sexy beast then </ComicalArrogance>

 

[FROGGBUSTER]

LOL, how did you get into dental school?

Oh. I am supposed to remember every fact from undergraduate chemistry? Oh yeah I forgot. Dental school has no new facts to memorize whatsoever. Everyday in class we discuss %yield. Dental school isn't stressful, either. All we do is talk about college chemistry. General chemistry. We don't have national boards or regional boards to worry about. Or patients. Or deadlines. Or labwork. Or a full 8-5 class day. Just memorize your basic chemistry. You're right I am dumb. All they do is reinforce it all day and all night.

So how did I get into dental school? The exact opposite from what you're doing...because you can't get in.

Uh oh.

 

[LetsGo2DSchool]

Oh. I am supposed to remember every fact from undergraduate chemistry? Oh yeah I forgot. Dental school has no new facts to memorize whatsoever. Everyday in class we discuss %yield. Dental school isn't stressful, either. All we do is talk about college chemistry. General chemistry. We don't have national boards or regional boards to worry about. Or patients. Or deadlines. Or labwork. Or a full 8-5 class day. Just memorize your basic chemistry. You're right I am dumb. All they do is reinforce it all day and all night.

So how did I get into dental school? The exact opposite from what you're doing...because you can't get in.

I hope you understand I was being playful with my comment. Of course we all forget the basic stuff that we learned months/years ago, not to mention what I ate for breakfast this morning...

 

[AlbinoPolarBear]

I hope you understand I was being playful with my comment. Of course we all forget the basic stuff that we learned months/years ago, not to mention what I ate for breakfast this morning...

Actually, these chemistry questions are pretty basic (high school), and it's pretty disappointing to see a D4 student not get it.

I hope the OP doesn't use his excuse of having bad retention of information when he's in private practice. "I last learned of this procedure 5 years ago! How am I supposed to remember??". He'll lose clients fast.

Let's not come in here and look down on us predents OP. After all, you're coming in here to ask us for help. 👍

 

[thefifthbeatle]

Actually, these chemistry questions are pretty basic (high school), and it's pretty disappointing to see a D4 student not get it.

I hope the OP doesn't use his excuse of having bad retention of information when he's in private practice. "I last learned of this procedure 5 years ago! How am I supposed to remember??". He'll lose clients fast.

Let's not come in here and look down on us predents OP. After all, you're coming in here to ask us for help. 👍

Very ignorant statement. Wait until you start school and see if you can remember chemistry and your sociology and your physics and your english literature, etc. I retain what I use. And you can bet I will not forget "procedures I learned 5 years ago" because they will be my livelyhood. Asking to convert moles is not. Why retain that? There is too much in my field to master. You will see in a little bit when you get into school. So don't judge.

I thanked both people profusely for their help. I am helping someone prepare for the DAT and before I tell them wrong info, i'd like some help/refresher. I don't see where the insults are necessary. I don't look down on the predents whatsoever...I was one 3.5 years ago!! I sympathize with you all. It is not fun. And it gets worse in school. I, however, don't need a "LOL how did you get into school?" by someone who is not even in.