Quantcast

Got Homework?

Connect with other students for help. It's a free community.

  • across
    MIT Grad Student
    Online now
  • laura*
    Helped 1,000 students
    Online now
  • Hero
    College Math Guru
    Online now

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

wondering_ Group Title

How many milligrams of C atoms are in 2.04 x 10^20 molecules of ethanol?

  • 2 years ago
  • 2 years ago

  • This Question is Open
  1. zepp Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    Ethanol: \(\large \text{C}_2\text{H}_6\text{O}\)

    • 2 years ago
  2. zepp Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    So first question, how many moles does 2.04 x 10^20 molecules represent?

    • 2 years ago
  3. wondering_ Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    its not CH(Sub 6)O?

    • 2 years ago
  4. wondering_ Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    why did u give Carbon2?

    • 2 years ago
  5. zepp Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    Because that's the formula for Ethanol

    • 2 years ago
  6. zepp Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    It's a 2-carbon alcohol.

    • 2 years ago
  7. wondering_ Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    \[(6.02 \times 10^{23})(2.04 \times 10^{20})?\]

    • 2 years ago
  8. wondering_ Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    oh ok

    • 2 years ago
  9. zepp Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    That's incorrect; \[\large 1 \text{ mole}= 6.02×10^{23}\]

    • 2 years ago
  10. zepp Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    \[\large ? \text{ mole}=2.04×10^{20}\]

    • 2 years ago
  11. zepp Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    That's a proportion and you should have this: \(\LARGE \frac{2.04×10^{20}}{6.02×10^{23}}\)

    • 2 years ago
  12. wondering_ Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    oh so its divide instead of multiply?

    • 2 years ago
  13. zepp Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    Yes, that's algebraic manipulation.

    • 2 years ago
  14. zepp Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    Once you get that, you'll get the number of moles this quantity of molecules represent, are afterward, you may convert that easily to its mass through the molar mass.

    • 2 years ago
  15. wondering_ Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    |dw:1349138080842:dw|

    • 2 years ago
  16. zepp Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    Why 1000?

    • 2 years ago
  17. wondering_ Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    for milligrams?

    • 2 years ago
  18. zepp Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    Our units are in moles...

    • 2 years ago
  19. zepp Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    \[\large \frac{1 \text{ mole}}{6.02*10^{23} \text{ atoms}}=\frac{x \text{ mole}}{2.04 * 10^{20}\text{ atoms}}\]Multiply both sides by 2.04*10^20\[\large \frac{2.04*10^{20}\text{ atoms}*1 \text{ mole}}{6.02*10^{23} \text{ atoms}}=x \text{ mole}\]

    • 2 years ago
  20. zepp Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    atoms and atoms simplify out, leaving the mole on both sides.\[\large \frac{2.04*10^{20}}{6.02*10^{23}}\text{mole}=x \text{ mole}\]

    • 2 years ago
  21. wondering_ Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    ok i see

    • 2 years ago
  22. wondering_ Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    i got .0003 correct?

    • 2 years ago
  23. zepp Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    You'll get as answer: \(\large x\text{ moles}\) Now you may proceed to transform this using \(\LARGE n=\frac{m}{M}\), where \(\large \text{n}\) is the number of moles, \(\large \text{m}\) is the mass in \(\large \textbf{grams}\) (so you'll need to retransform it into milligrams as you're asked to do) and \(\large \text{M}\) is the molar mass.

    • 2 years ago
  24. wondering_ Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    Molar mass is 46.07?

    • 2 years ago
  25. zepp Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    Yes

    • 2 years ago
  26. wondering_ Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    well for ethanol it self right?

    • 2 years ago
  27. wondering_ Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    would i multiply that by .0003

    • 2 years ago
  28. zepp Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    Exact.

    • 2 years ago
  29. wondering_ Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    46.68->46.7 sorry

    • 2 years ago
  30. wondering_ Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    so i got .0140 because i used 46.68*.0003

    • 2 years ago
  31. wondering_ Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    thats just grams right?

    • 2 years ago
  32. zepp Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    Yep

    • 2 years ago
  33. wondering_ Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    .0140 x 10^-3 ?

    • 2 years ago
  34. zepp Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    Good, now you'll need to set up another proportion:\[ \frac{\text{Mass of Carbon in 1 mole of Ethanol}}{\text{Molar mass of Ethanol}}=\frac{\text{Mass of Carbon (Unknown) }}{\text{Mass of the Ethanol given to you}}\]

    • 2 years ago
  35. wondering_ Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    (?/46.68)=(?/.0140x10^-3?)

    • 2 years ago
  36. zepp Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    Mass of carbon in 1 mole of ethanol is a known number, 2*Molar mass of carbon, 12, 2*12 = 24.

    • 2 years ago
  37. wondering_ Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    oh ok i see where you got that from

    • 2 years ago
  38. wondering_ Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    (24/46.68) = (?/.0140x10^-3?)

    • 2 years ago
  39. wondering_ Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    was i correct on the second half too?

    • 2 years ago
  40. zepp Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    I don't know, I didn't push the values in my calculator, I've shown you how to do these kind of problem, all the other mathematical manipulations/calculations should be done by you; the right method is shown so you can take down any question that looks like this.

    • 2 years ago
  41. wondering_ Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    I was asking about for the mass of the ethanol that the answer i found before right?

    • 2 years ago
  42. zepp Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    Like I said, I don't know :)

    • 2 years ago
  43. wondering_ Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    Ok so now i simple mult across top and bottom and cancel out to get my answer

    • 2 years ago
  44. wondering_ Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    simply*

    • 2 years ago
  45. wondering_ Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    i think i have it

    • 2 years ago
  46. wondering_ Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    thank you

    • 2 years ago
  47. zepp Group Title
    Best Response
    You've already chosen the best response.
    Medals 2

    np

    • 2 years ago
    • Attachments:

See more questions >>>

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.