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Homework Help: Reaction Lab (NEED HELP )

  1. Nov 3, 2009 #1
    Reaction Lab (NEED HELP!!)

    1. This is a clock reaction lab where you have 10mL of KIO3 solution in a beaker, and you are adding 10mL of NaHSO3 solution to it. You then start the stopwatch and wait until the solution turns blue. I need to calculate the initial concentrations of KIO3 in each of the mixtures for part A after mixing. There are trials in total, and I will show my data as well. There is always 10mL of NaHSO3 in the beaker.
    Trial 1: Add 10mL KIO3
    Trial 2: Add 7mL KIO3 and 3mL Water
    Trial 3: Add 5mL KIO3 and 5mL Water
    Trial 4: Add 3mL KIO3 and 7 mL Water

    My Teacher says to use the formula C1V1=C2V2, but I don't know which values to put where.

    *Note: Concentration of KIO3= 0.0200 mol/L
    Concentration of NaHSO3= 0.00200 mol/L

    3. My Attempts:

    I have tried for Trial one and this is what I got:
    C1=what I am solving for
    V1=10.00 mL
    C2=0.00200 mol/L
    V2=20.00 mL

    =0.00200 mol/L x 20.00 mL/10.00mL
    =0.004 mol/L

    Is this right? I just don't get what to do for the next 3 trials because water is added?

    Thanks so much!
    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution
  2. jcsd
  3. Nov 3, 2009 #2


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    Re: Reaction Lab (NEED HELP!!)

    You could us the variables subscripted as 1 for initial C and V, and subscripted 2 for final C and V.
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