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?

## Answer This Question

## Related Questions

- Chemistry - Hi DrBob, Sorry about that, I wasn't very clear! Can someone please ...
- CHemistry Please Help. DR. BOBB - Standardization of the Sodium Thiosulfate ...
- DrBobb222 : Chemistry HElp...Please Check - Standardization of the Sodium ...
- CHemistry Please Help..............LAB - Standardization of the Sodium ...
- DrBob222 : Chemistry HElp...Please Check - Sorry its not letting me post the ...
- Chemistry - Please check my answers. 1. Using the equations, IO3- +5I- + 6H+ -&...
- Chemistry: please double check... - Please double check one last time have to ...
- Chemistry - What mass of KIO3 is needed to convert the copper in 0.200g of CuSO4...
- Chemistry - Calculate the number of moles of KIO3 consumed by reaction (2.1). ...
- chemistry, - in analyzing household bleach. I have a flask that contains 10.00 ...

More Related Questions