Calculating Initial Concentrations for Clock Reaction Lab | Trial Data Included

[ashley_s_411]

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

c1=c2v2/v1
=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!

Homework Statement

Homework Equations

The Attempt at a Solution

 

[symbolipoint]

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