Chemistry questions

[Utopify]

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I did not see a specific forum advocating educational stuff:

1. How many atoms are in 12 molecues of fructose (C6 H12 06)
A:24
B:288
C:2160
D:72
E:1.73x10^26

My answer was E, but I have no idea. I just took number of molecules, times avagardro's #....????

2. What is the TOTAL concentration (in molarity, M) of ions in a 0.0360 M solution of NA2 CO3?

I appreciate ANY and ALL help and explanations.

-dallas

 

[fpr85]

I did not see a specific forum advocating educational stuff:

1. How many atoms are in 12 molecues of fructose (C6 H12 06)
A:24
B:288
C:2160
D:72
E:1.73x10^26

Wouldn't it just be (6 + 12 + 6) * 12?

B?

 

[liverotcod]

1. B - the question asks about molecules, not moles, so it's (24 atoms/molecule) * (2 molecules) = 288 atoms.
2. There are 3 moles of ions per mole of Na2CO3. So (0.0360 mol/liter) * (3 ions/mol) = 0.108 M.

You might try the MCAT forum for this kind of question. But if it's homework help you're looking for, that's generally frowned on at SDN, in my experience.

 

[Utopify]

Why is it frowned upon? "STUDENT" doctor network....hmmmmm

Well, I appreciate the feedback. How did you get "3 moles of ions per mole of Na2CO3?"

Thanks again...I guess I'll start looking for a chemistry forum maybe? Or maybe we should rename this forum to "Med School Applicant Network" MSAN.net if students are not welcome to ask ?'s....ya know?

-dallas

 

[MadameLULU]

Why is it frowned upon? "STUDENT" doctor network....hmmmmm

Well, I appreciate the feedback. How did you get "3 moles of ions per mole of Na2CO3?"

Thanks again...I guess I'll start looking for a chemistry forum maybe? Or maybe we should rename this forum to "Med School Applicant Network" MSAN.net if students are not welcome to ask ?'s....ya know?

-dallas

Na2CO3 will break up into 2 moles of Na and 1 mole of CO3 for a total of 3 moles of ions.

 

[Johnisit1234]

Why is it frowned upon? "STUDENT" doctor network....hmmmmm

Well, I appreciate the feedback. How did you get "3 moles of ions per mole of Na2CO3?"

Thanks again...I guess I'll start looking for a chemistry forum maybe? Or maybe we should rename this forum to "Med School Applicant Network" MSAN.net if students are not welcome to ask ?'s....ya know?

-dallas

Well it is student doctor, but it's not homework help dot com

 

[liverotcod]

Why is it frowned upon? "STUDENT" doctor network....hmmmmm

Because questions like the one you asked should be well covered by your textbook, your classroom instructors &c.

You're not likely to actually learn the material without doing the legwork to research questions on your own.

Asking questions about course material isn't bad. For example, you might say, "I've been searching my textbook and just can't figure out why you get three ions from on Na2CO3. Any suggestions?" That way you show that you're not just looking to finish up your homework and get back to video games, or whatever. Not that I'm implying that that's your goal. It just seems that way when you post specific multiple choice questions.

 

[Phased]

I did not see a specific forum advocating educational stuff:

1. How many atoms are in 12 molecues of fructose (C6 H12 06)
A:24
B:288
C:2160
D:72
E:1.73x10^26

My answer was E, but I have no idea. I just took number of molecules, times avagardro's #....????

2. What is the TOTAL concentration (in molarity, M) of ions in a 0.0360 M solution of NA2 CO3?

I appreciate ANY and ALL help and explanations.

-dallas

1. 6 moles C, 12 moles H, 6 moles O in 1 mole of C6H12O6. In 12 moles of C6H12O6, theres -> (6+12+6)*12 = 288 moles of C, H, and O. Avagadro's number is using to convert moles into atoms (288 moles * 6.022e23 atoms/mole). 1.7e26 atoms.

2. Na2CO3 -> 2NA(+) + CO3(-2), 3 moles. So total ion concentration would be 3 ions / mol * 0.0360 M = 0.108 ions/L.

 

[fpr85]

Because questions like the one you asked should be well covered by your textbook, your classroom instructors &c.

You're not likely to actually learn the material without doing the legwork to research questions on your own.

Asking questions about course material isn't bad. For example, you might say, "I've been searching my textbook and just can't figure out why you get three ions from on Na2CO3. Any suggestions?" That way you show that you're not just looking to finish up your homework and get back to video games, or whatever. Not that I'm implying that that's your goal. It just seems that way when you post specific multiple choice questions.

Yeah, even I got it, lol (I just say this cause I'm a freshie in undergrad ). I probably would've been able to answer the second but had to run to my bio class, and the test, by the way, went pretty well! Hoping for at least an A! *keeps fingers crossed*

1. 6 moles C, 12 moles H, 6 moles O in 1 mole of C6H12O6. In 12 moles of C6H12O6, theres -> (6+12+6)*12 = 288 moles of C, H, and O. Avagadro's number is using to convert moles into atoms (288 moles * 6.022e23 atoms/mole). 1.7e26 atoms.

I thought that moles/molecules was when it was in front of the atomic symbol? When it's down below it means # of atoms?

Boy I feel dumb 🙄

 

[Utopify]

Well, I had a bunch of homework, these two I could not find/figure based on my text/lecture notes, and the question itself.

Phased's answer to part one makes the most sense. Just 288 is the moles of the substance.

And, as far as playing video games? I am 26, at work (for the Air Force), and my time is taxed. I apoligize for coming off as a 'student' looking for easy answers. I still do not understand ion calculation, but will see what I can find.

Thanks again for the feedback,

Dallas

 

[fpr85]

Well, I had a bunch of homework, these two I could not find/figure based on my text/lecture notes, and the question itself.

Phased's answer to part one makes the most sense. Just 288 is the moles of the substance.

And, as far as playing video games? I am 26, at work (for the Air Force), and my time is taxed. I apoligize for coming off as a 'student' looking for easy answers. I still do not understand ion calculation, but will see what I can find.

Thanks again for the feedback,

Dallas

Don't worry about it.
I feel bad, he's a newcomer and we've already given him a negative impression of SDN 😳

 

[Phased]

I thought that moles/molecules was when it was in front of the atomic symbol? When it's down below it means # of atoms?

😱

There is a difference between a mole and a molecule. A molecule is a collection of atoms bonded to each other. A mole is a number, defined by the number of atoms in exactly 12 g of 12C...i.e. Avagadro's number, 6.022e23. As far as your interpretation of the periodic table, uhm...lol, top is atomic number, bottom is atomic mass. Being a freshman is no excuse, God damn it I'm a freshman too.

I still do not understand ion calculation, but will see what I can find.

What part of it is difficult for you? Na2CO3 breaking up into it's ions, or the ion concentration? Take for example the ionic compound NaCl, when you mix it in water it'll break into Na+ and Cl- ions. Which is a total of two: 1 Na+ and 1 Cl-. Na2CO3 breaks up into Na+ and CO3- ions, which is a total of three: 2Na+ and CO3- (the original compound is Na2 CO3).

 

[group_theory]

Hmm ... for most people who have difficulty calculating ion concentration, the hardest part is recognizing what ions break apart when in water/solution.

It would be helpful if you take the time to recognize common ions. An example would be OH, or SO4, NO3, CO3, MnO4, etc. You'll see these ions appear again and again in general chemistry as well as organic chemistry

If you see something like NaOH, you will know that it breaks up into Na and OH, not Na, O, and H. (2 ions instead of three). I hope this helps.

 

[liverotcod]

It would be helpful if you take the time to recognize common ions. An example would be OH, or SO4, NO3, CO3, MnO4, etc.

Good advice. As I recall we were required to memorize both the common ions and their charges for our first genchem exam. It's one of those things that, once you get used to it, is difficult to remember not knowing. Sorry for being rude, earlier.

 

[fpr85]

😱

There is a difference between a mole and a molecule. A molecule is a collection of atoms bonded to each other. A mole is a number, defined by the number of atoms in exactly 12 g of 12C...i.e. Avagadro's number, 6.022e23. As far as your interpretation of the periodic table, uhm...lol, top is atomic number, bottom is atomic mass. Being a freshman is no excuse, God damn it I'm a freshman too.

😕 I must not have made it clear what I was asking, I know what you just stated, but then again I was probably freaking out because I had a biology test up next and I was starting to confuse myself reading all of this 😀