• Lucid Dreaming - Dream Views




    Results 1 to 14 of 14
    Like Tree2Likes
    • 1 Post By SnakeCharmer
    • 1 Post By Philosopher8659

    Thread: Mind helping me to solve this stoichiometry problem?

    1. #1
      Member
      Join Date
      Oct 2009
      Posts
      6,310
      Likes
      2026

      Mind helping me to solve this stoichiometry problem?

      According to my teacher, it's easy, but for my whole class, it isn't.

      Unknown element X combines with oxygen to form the compound XO2. If 44.0 grams of element X combines with 8.00 grams of oxygen, what is the atomic mass of element X?

      A. 16 amu
      B. 44 amu
      C. 88 amu
      D. 176 amu
      E. 352 amu
      I'd appreciate the help and preferably a quick explanation, because no one understands it and our teacher is giving limited hints out. Thanks.

    2. #2
      Dismember Achievements:
      1000 Hall Points Veteran First Class
      SnakeCharmer's Avatar
      Join Date
      Mar 2009
      Gender
      Location
      The river
      Posts
      245
      Likes
      41
      X + O2 --> XO2

      m (O2) = 8 g
      M (O2) = 32 g/mol

      This means that 8/32=0.25 moles of oxygen reacted with 0.25 moles of X

      m (X) = 44 g is equivalent to 0.25 mol of X

      Atomic mass of X should be 44/0.25 = 176

      EDIT: sorry M(O2) = 32, not 16 like I originally wrote
      Last edited by SnakeCharmer; 10-14-2010 at 05:50 PM.
      Puffin likes this.

    3. #3
      Member
      Join Date
      Oct 2009
      Posts
      6,310
      Likes
      2026
      Thank you!

    4. #4
      Banned
      Join Date
      Nov 2007
      Gender
      Posts
      1,674
      Likes
      200
      Well I would have done it simpler.

      For a one to one correspondence, O2 would be divided into 2, or 4 to 44 which is 11, then simply multiply. 11 x 16 for 176.

      4 is to 44 as 16 is to 176.
      Last edited by Philosopher8659; 10-14-2010 at 05:56 PM.
      Puffin likes this.

    5. #5
      Xei
      UnitedKingdom Xei is offline
      Banned
      Join Date
      Aug 2005
      Posts
      9,984
      Likes
      3082
      I'm not sure what we should do about these kind of threads.

      I don't have any problem with answering general questions, but when it gets to basically doing homework for people... I'm not so sure that's a good idea.

      Plus it's not really extended discussion... perhaps there should be a subforum for this kind of thread? Thoughts?

    6. #6
      Banned
      Join Date
      Nov 2007
      Gender
      Posts
      1,674
      Likes
      200
      I am not too keen on overly established formalities that really boil down to subjective non-sense. What is homework but the instilling of ideas to begin with? It often happens that one lacks the conception expressed in an idea, and thus makes faulty judgments. Best to err on the side of liberality than of stupidity.

    7. #7
      Member
      Join Date
      Oct 2009
      Posts
      6,310
      Likes
      2026
      Quote Originally Posted by Xei View Post
      I'm not sure what we should do about these kind of threads.

      I don't have any problem with answering general questions, but when it gets to basically doing homework for people... I'm not so sure that's a good idea.

      Plus it's not really extended discussion... perhaps there should be a subforum for this kind of thread? Thoughts?
      I'm not big on it either, but that's why I asked for an explanation so I understand the concept. And this is in Science and Mathematics, which is appropriate. As for it being in extended discussion, well... :p

    8. #8
      Banned
      Join Date
      Nov 2007
      Gender
      Posts
      1,674
      Likes
      200
      If you keep asking for understanding, you just might end up a philosopher, then watch out. big trouble.

    9. #9
      Xei
      UnitedKingdom Xei is offline
      Banned
      Join Date
      Aug 2005
      Posts
      9,984
      Likes
      3082
      You weren't really told how to do it though, you were just given the workings... I'd much rather somebody said something like, 'what two things do you need to work out the atomic mass?', 'how can we obtain these from the question?', etcetera.

    10. #10
      Banned
      Join Date
      Nov 2007
      Gender
      Posts
      1,674
      Likes
      200
      Oh crap, not only where to say something by how. I don't have a gun, so I will just ask for an explanation on how to shoot myself without a gun.

    11. #11
      Xei
      UnitedKingdom Xei is offline
      Banned
      Join Date
      Aug 2005
      Posts
      9,984
      Likes
      3082
      I have no idea what you're talking about, but you should understand as always that I wasn't talking to you anyway, I was talking to the original poster.

    12. #12
      Banned
      Join Date
      Nov 2007
      Gender
      Posts
      1,674
      Likes
      200
      Pardon me, I was misled into believing this was a forum. Not a twosome. Besides, I have adopted her as my soulmate, it is called virtual perversion.

    13. #13
      Xei
      UnitedKingdom Xei is offline
      Banned
      Join Date
      Aug 2005
      Posts
      9,984
      Likes
      3082
      There's a difference between being free to talk to everybody and being obliged to, and I found your comments on my conversation incomprehensible so I thought I should let you know that I'm not replying to them.

    14. #14
      Banned
      Join Date
      Nov 2007
      Gender
      Posts
      1,674
      Likes
      200
      Okay, but you can still play with my toys.

    Similar Threads

    1. Replies: 3
      Last Post: 03-31-2008, 04:44 PM
    2. Tell me how to solve this
      By ninja9578 in forum Ask/Tell Me About
      Replies: 15
      Last Post: 03-16-2008, 03:12 PM
    3. The mind-body problem
      By Crumbs in forum Philosophy
      Replies: 8
      Last Post: 05-20-2007, 04:10 AM
    4. One Problem Solve Need Another Solution
      By wendylove in forum Dream Control
      Replies: 6
      Last Post: 04-09-2007, 09:54 PM
    5. Problem Drawing Images From My Mind
      By ilovefrootloopz in forum Artists' Corner
      Replies: 4
      Last Post: 10-21-2006, 11:11 AM

    Tags for this Thread

    Bookmarks

    Posting Permissions

    • You may not post new threads
    • You may not post replies
    • You may not post attachments
    • You may not edit your posts
    •