GROUP 3Azis Dwi Septianto

Billy Dimas Anggoro

Maghfira Firstia Mulyawan

Mohammad Suhud Farabi

Prambudi Cahyo Laksono

Prasetia

Definition of Indicator

Yodometri Indicator

Kanji’s Indicator

Example of Yodometri Titration

Definition of

IndicatorIndicator is a chemical

substrate that added into a

titration which give a change of

color when the endpoint

reached.

Indicator usually used at

a reaction of titration that

the change is invisible or

only just to clear a

Yodometri

IndicatorTitration in yodometric actually

can do without the addition of

indicator from outside because the

color that produce by I2 that

titrated by Tio will be dissolved

when endpoint reached.Generally, first the change of the color is dark

brown, then become light brown, then turn intoyellow, light yellow, until in the end the color ofsolution will be disappear.

When it observed, the color is

clear enough because the

There are several types of

indicators may be used in redox

titration. Among them are the

specific indicators, are

substances that cause reactions

in a specific way with one of the

reactants in the titration to

produce colors such as dark

blue starch with iodine.

make starch as an important

energy source.

Amylum or starch is a

Kanji can be separated

into two primary

components such amylose

( ) which long and straight

chain, is abundant in potato

starch , and gives blue color

with Yod. And amylopectin

( ) which has a long chain

but branched, and form a

product that purple–red.

Amylose

Amylopectin

In daily language, word

“starch” always mixed with

“flour” and also “kanji”.

Starch is a primary compose of

flour. Flour can be may not

only contain pure starch, it can

be mixed or blended with

protein, vitamins, and other

materials contained in the

grains of rice.

C o l o r e d c o m p l e x

f o r m a t i o n m e c h a n i s m

i s n o t p r e c i s e l y

k n o w n . H o w e v e r , t h e

i o d i n e m o l e c u l e s

a r e h e l d o n t h e

s u r f a c e o f a m y l o s e , a

s t a r c h e l e m e n t .

E l e m e n t s o f o t h e r

s t a r c h a m y l o p e c t i n

f o r m a c o m p l e x t h a t

i s r e d d i s h (v i o l e t )

w i t h i o d i n e , w h i c h i s

it’sthat

amylopectinindicator.

easilyit

addition,

The main advantage of kanji is cheap.

But the disadvantages, such as:

1. Insoluble in cold water

2. Unstable suspense in water

3. With Iod give a complex that insoluble in

water, so kanji can’t be added in the

beginning of the titration.

Kanji can’t be added into a highly acidic

medium because it can occurs hydrolysis

of the kanji. And also the addition of the

etanol 50% or more because the color

won’t be appear.

The Example Of

Yodometri Titration

Y o d o me t r i i st i t r a t i o n w i t h r e d o xme t h o d . T h i st i t r a t i o n i s i n d i r e c tt i t r a t i o n , w h e r en e e d e d o t h e rs u b s t a n c e b e f o r et i t r a t e d w i t h T i os o l u t i o n .

A n d t h i s i s a ne x a mp l e o f s u b s t a n c et h a t i t p e r c e n t a g ec a n b e d e t e r mi n a t e d

T h i s p r o c e d u r e b a s e

o n r e a c t i o n b e t w e e n

c h l o r a t a n d i o d i d e

w i t h c o n c e n t r a t e d

c h l o r i d e a c i d :

i o d t h a t p r o d u c e d a r e

t i t r a t e d w i t h T i o

s o l u t i o n .

I n o t h e r m e t h o d e ,

t h i s c h l o r a t i s

r e d u c t e d w i t h b r o m i d e

O3H3ICl6HI6ClO 22

---

3

O3H3BrCl6H6BrClO 22

---

3

Determination The Content of

Cu (II) in CuSO4.5H2O by “De

Haens” WayIn acidic conditions, Cu (II) can be

reduced to CuI2 which then decompose intoCu2I2 and I2. Thereafter, the free I2 titratedwith Na2S2O3 (sodium thiosulfate) andstarch indicator when approaching theendpoint. Cu (II) reduced by KI. The endpoint of this designation is from blue tocolorless and milky white precipitateformed.

Reaction

422

4 SOK2white

2CuI 4KI 2CuSO

222

2 Iemilky whit

ICuCuI2

6423222 OSNa NaI2OS2NaI

Determination of

Normality of Na2S2O3

with BBP KIO3In acidic conditions, can be

oxidized by KIO3 KI to iodine (I2)

that have free brown. Free I2 then

titrated with Na2S2O3 until a

slight yellow color. The addition

of starch as an indicator of the

blue and make the solution

obtained colorless endpoint.

OH3I3KCl6HCl6KI5KIO 223

6423222 OSNa NaI2OS2NaI

Any Question So Far?