Just one sec...
Hey! Sign in to get help with your study questionsNew here? Join for free to post

Chemistry RAM help

Announcements Posted on
Take our short survey, £100 of Amazon vouchers to be won! 23-09-2016
    • Thread Starter
    Offline

    1
    ReputationRep:
    Can someone help me with this question!

    A mass spectrum of a sample of antimony showed two peaks at m/z= 120 and m/z= 122. The relative atomic mass of this sample of antimony is 121.3. Use these data to calculate the ratio of the relative abundances of the two isotopes.
    Offline

    1
    ReputationRep:
    Just did it- pic will follow
    Offline

    1
    ReputationRep:
    Name:  ImageUploadedByStudent Room1474229978.891840.jpg
Views: 18
Size:  143.1 KB


    Posted from TSR Mobile
    Offline

    3
    ReputationRep:
    (Original post by ohmickeyursofine)
    Name:  ImageUploadedByStudent Room1474229978.891840.jpg
Views: 18
Size:  143.1 KB


    Posted from TSR Mobile
    Your answer is wrong. 122 must be more abundant than 120 as the relative atomic mass is 121.3
    Offline

    3
    ReputationRep:
    (Original post by Naya104)
    Can someone help me with this question!

    A mass spectrum of a sample of antimony showed two peaks at m/z= 120 and m/z= 122. The relative atomic mass of this sample of antimony is 121.3. Use these data to calculate the ratio of the relative abundances of the two isotopes.
    121 = 50:50 abundance

    Therefore, each 0.5 is worth 25% abundance
    Therefore, each 0.05 is worth 2.5% abundance

    121 + 0.05 x 6 = 121.3

    6 0.05s therefore 2.5 x 6 = 15%

    50 + 15 = 65

    Ratio is 35:65
    Offline

    1
    ReputationRep:
    Oh sorry woops it's been a long day- did it the wrong way round, it would be 120x and 122(100-x)
    Offline

    1
    ReputationRep:
    Name:  ImageUploadedByStudent Room1474231113.642063.jpg
Views: 9
Size:  130.1 KB


    Posted from TSR Mobile
    Offline

    1
    ReputationRep:
    The other method works just as good- at least someone noticed the mistake!
    • Thread Starter
    Offline

    1
    ReputationRep:
    Thank you
 
 
 
Write a reply…

Reply

Submit reply

Register

Thanks for posting! You just need to create an account in order to submit the post
  1. this can't be left blank
    that username has been taken, please choose another Forgotten your password?
  2. this can't be left blank
    this email is already registered. Forgotten your password?
  3. this can't be left blank

    6 characters or longer with both numbers and letters is safer

  4. this can't be left empty
    your full birthday is required
  1. Oops, you need to agree to our Ts&Cs to register
  2. Slide to join now Processing…

Updated: September 21, 2016
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

Poll
Who will be the next permanent England boss?

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.