# Weight percent of hypochlorite in bleach

1. Oct 14, 2009

### ~Sam~

1. The problem statement, all variables and given/known data
If 5 mL of a bleach sample is diluted to 100 mL and then 30.00 mL of the dilute solution is titrated with 29.65 mL of a 0.1034 M solution of thiosulfate what is the weight percent of hypochlorite in the 5 mL of bleach?

2. Relevant equations
OCl−(aq) + 2I−(aq) → I2(aq) + Cl−(aq)
First hypochlorite is reacted with idiode

then we titrate the I2 with thiosulfate
I2(aq) + S2O32−(aq) →I−(aq) + S4O62−(aq)

3. The attempt at a solution

I started by finding moles of thiosulfate and related to I2 and relate back to the hypochlorite OCl- then I used those moles to mass of the OCl- and then after that I'm not sure what to do.

2. Oct 14, 2009

### chemisttree

Knowing moles can you tell us how much it (NaOCl) might weigh?

Are you asked for a weight percent based on volume (weight/volume) or based on weight (weight/weight) of the original bleach solution?

3. Oct 20, 2009

### ~Sam~

Based on volume, per 100 mL

4. Oct 21, 2009