Posted by Bryant on Sunday, March 6, 2011 at 9:06pm.
Can someone please help me complete these calculations for my lab; I am having some trouble.
A. Standardization of Na2S2O3
Mass of KIO3 in 100mL = 0.09600g
Calculate Molarity of KIO3= ?
Please check: 0.09600g/(214.0g/mol)=4.486x 10^4 mol
4.486 mol/0.1L= 44.86 M
B. Titration/ Volume of Na2S2O3
1: 38.44 mL
2: 37.23 mL
3: 38.11 mL
Average Volume: 37.93mL
Calculate molarity of Na2S2O3=?
Not sure what to use as the mass here? Help
C. V of Bleach= 1.020
V of Na2S2O3= 2.010
Calculate Mass of NaOCl/100mL bleach=? Help with this.
Thanks.

Chemistry  DrBob222, Sunday, March 6, 2011 at 10:40pm
I think you have several problems before you start. First, I don't think the M of the KIO3 can be a number such as about 45 M. That's just too large.
Second, have you shown all of your reactions? Usually one doesn't titrate KIO3 with Na2S2O3. Are you adding KI to the solution, then titrating the liberated I2 with Na2S2O3?. If so, where is the equation for the I2?
Third, in the titration step with OCl^, did you add I2 to that and you titrated the liberated I2 with Na2S2O3? If so you need an equation for that.
Fourth, and final, V of bleach is 1.020 WHAT UNIT and V Na2S2O3 2.010 WHAT UNIT?