Analysis of bleach redox titration lab

Shows the process of competing an iodometric titration of household bleach. Please note that it would have been a safer choice to wear nitrile gloves. If you perform the experiment, please wear appropriate PPE.

Equations:
When dissolved in water, the NaOCl in bleach dissociates into its ions:
NaOCl(s) → Na+(aq) + OCl1-(aq)
The OCl1- ion then reacts with water to from hypochlorous acid:
OCl1-(aq) + H2O(l) ⇌ HOCl (aq) + OH1-(aq)
The HOCl reacted with excess iodide ions under acidic conditions:
HOCl(aq) + 2I1-(aq) + H1+(aq) → I2(aq) + Cl1-(aq) + H2O(l)
The iodine that forms is then titrated with a standard sodium thiosulfate solution:
2S2O32-(aq) + I2(aq) → 2I1-(aq) + S4O62-(aq)

[lygldyy]

Any chance you can talk me through the uncertainty calculation for this lab?

[cloethegleemo]

Hello,

Why can you add acid to bleach here? Normally when acid is added to a bleach solution, which contains ClO- and Cl-, chlorine gas will form, which is dangerous to inhale. Is it just such small amounts that it doesnt matter here?

[pixelscanon]

When I did this lab, I measured my diluted bleach exact and something went wrong and it stayed brown ;( this video is great, my lab doesn’t have the electronic mixer, I wonder what I did wrong. Stay safe! Make more videos! 💫

[radhikaiyer]

No doubt its well planned but i do not understand why you wash it down in between? would that not dilute and bring about change in endpoint ?

[radhikaiyer]

why no PPE being worn while handling bleach?