Notices
Results 1 to 1 of 1

Thread: chemistry calculation help please

  1. #1 chemistry calculation help please 
    New Member
    Join Date
    Nov 2017
    Posts
    3
    Hi im sorry i dont know if this is the correct forum to ask this question in but here it is:
    I need to calculate the riboflavin content for a solution. It was made from 1 vitamin tablet dissolved in 20ml of water. Then the solution was made up to 100ml with neutral buffer. Then a 1:50 dilution was made with the solution. The concentration of riboflavin in the 1:50 solution was 86 μg/L. I need to know the riboflavin content in the tablet, in mg. Could anyone be kind enough to help me with this please. Thank you.


    Reply With Quote  
     

  2.  
     

  3. #2  
    Bullshit Intolerant PhDemon's Avatar
    Join Date
    Feb 2013
    Location
    Newcastle-upon-Tyne, UK
    Posts
    4,550
    Before the 50X dilution the concentration would be

    50 x 86 = 4300 ug/L

    As the sample was made up of 100 ml pre dilution this would contain 430ug. So your tablet contains 430ug of riboflavin.


    Reply With Quote  
     

  4. #3  
    New Member
    Join Date
    Nov 2017
    Posts
    3
    so from what i understand the concentration of riboflavin would be 430 ug in 100ml of solution? which is basically 4300ug/L ?
    Reply With Quote  
     

  5. #4  
    Bullshit Intolerant PhDemon's Avatar
    Join Date
    Feb 2013
    Location
    Newcastle-upon-Tyne, UK
    Posts
    4,550
    Yes, you dissolved the tablet in 20 ml and then made it up to 100 ml. So the concentration is 430 / (100/1000) = 4300 ug/L. You then diluted this by a factor of 50 to give a final concentration of 4300/50 = 86 ug/L.
    Reply With Quote  
     

  6. #5  
    New Member
    Join Date
    Nov 2017
    Posts
    3
    thank you very much for your help
    Reply With Quote  
     

  7. #6  
    Bullshit Intolerant PhDemon's Avatar
    Join Date
    Feb 2013
    Location
    Newcastle-upon-Tyne, UK
    Posts
    4,550
    No problem.
    Reply With Quote  
     

Similar Threads

  1. Replies: 5
    Last Post: January 8th, 2013, 01:13 PM
  2. calculation
    By zxcv in forum Chemistry
    Replies: 1
    Last Post: March 2nd, 2009, 05:49 PM
  3. Calculation!!!!
    By qirmiz in forum Chemistry
    Replies: 0
    Last Post: June 26th, 2008, 04:28 AM
  4. calculation
    By jssb in forum Mathematics
    Replies: 1
    Last Post: May 2nd, 2006, 10:56 PM
  5. calculation
    By jssb in forum Physics
    Replies: 3
    Last Post: April 30th, 2006, 08:25 PM
Bookmarks
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
  •