Question

A 0.601 g sample of bleach was treated with an excess of Kl. The lodine liberated required 12.34 mL of 0.0692 M Na2S203 for titration What is the percentage of KOCI in the bleach? And can we use Nal to replace Kl in the titration? Why?

Answer 1

1
The chemical meartoon betaney lêberated rodire Lt) and Massa es- 2 olasz + 1₂ Na₂O + Zalah ec 2 mole of massage will tetrate a mole How güven makes of was usef= concentration avalume 0-0692m x 12:34 onl a. o692 mole X 12-34 onl 1000 ml 0.000854 moley That meam moles of Iz tibrated = 0.000859 2 0.000427 mole So we can say 0.000427 Dolay of La lebirated from the reactor of bleach and KI

noo the reaction betriem bleach and a takes place as Oct +20 +241 It is the produced from ere & mole of In es prodweed from I mole of ou .. we can say I mole of Iz is the neaction of a mole kos This 0.000427 moles of Iz is produced from = 0.000427 male koel This makes of koel present in bleach 20:0024 of koel present a moles x molar man of koel They man -0.000427 mde x90.558 mole = 0.639% ofkoch is bleach so- So mass % X100 man of koel man of bleach 0-0398 x 100 horborg 16+43 7 2

No here we can't take NaI instead of KI Because KI is less hygriscopic than NaI. Thus when we take KI , it does not bind with the moisture present. So the mass of KI taken comes to be accurate. So KI is used as a primary standard solution