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Homework Help: How to prepare 500 mL of 0.025 M of Glucose solution?

  1. Sep 17, 2017 #1
    1. The problem statement, all variables and given/known data:
    I am using a virtual chemistry laboratory and the directions for the first lab experiment says to prepare 500 mL of 0.025 M of glucose solution by diluting the 1 M glucose solution. (I am re-posting this question due to the fact that the previous one was deleted because it wasn't placed in the appropriate forum.)



    2. Relevant equations
    Prepare: 500 mL of 0.025 M of glucose solution by diluting the 1 M(1 Mole) of glucose solution with distilled water.



    3. The attempt at a solution
    I am not sure what to do here and I don't know what I am supposed to multiply. I tried adding the diluted water to it, but it said that it would overflow because I had added 400 mL of the diluted water. It said to indicate in the report, which solutions were mixed together and the amounts of each, but I am not sure how to mix them. I take it the M stands for Moles? And mL stands for mililiters. Do I divide 500 by 1000mL first?
     
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  3. Sep 17, 2017 #2

    Ygggdrasil

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    How many moles of glucose are in 500 mL of a 0.025 M solution of glucose?

    How many mL of a 1 M solution of glucose contains that number of moles of glucose?
     
  4. Sep 17, 2017 #3
    0.0125 X 1000 = 12.5 mL?
     
  5. Sep 17, 2017 #4
    answer to your first question 1) 500/1000 X 0.025 moles of solution = 0.0125 moles?
    answer to your second question 2) 0.0125 X 1000 = 12.5 mL?
     
  6. Sep 17, 2017 #5

    Ygggdrasil

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    Correct. To make 500 mL of a 0.025 M solution of glucose, you would take 12.5 mL of a 1 M solution of glucose, and add water to that until the final volume is 500 mL.

    An easier way remember this approach is the formula M1V1 = M2V2.

    In this case, the calculation would be 1M * V1 = 0.025M * 500mL. If you solve for V1 you would get 12.5 mL (essentially the same calculations as you presented above, just placed into one single formula).

    Alternatively, you can calculate the "fold dilution." 1 M / 0.025 M = 40, so you are performing a 40-fold dilution. That means you would take 500 mL/40 = 12.5 mL of 1M glucose and dilute to 500 mL.
     
  7. Sep 17, 2017 #6
    Thank you!
     
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