Page 84 - Statistics presented by Dr. Sara Ismail Aborass
P. 84
9/8/2023
Ester value
Number of mg of KOH required to saponify the esters in 1 g of the
substance (indication for combined fatty acids present)
Ester value = SPV − AV
Iodine value
Number of g of iodine absorbed by 100 g of the substance
Ex: 1.5 g of iodine is absorbed by 1 g of fat , IV = 150
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Determination
The reaction is based on the addition of halogen across a C=C double bond
Iodine bromide/gl acetic acid “Hanus reagent” is more reactive than Iodine
Iodine chloride/gl acetic acid "Wijs reagent" can be used instead.
Wt of substance examined, dissolve in organic solvent, add known volume of st.
iodine bromide /gl acetic acid "Hanus reagent". Keep in dark for 30 min. Add
KI solution and titrate the liberated iodine ≠ st Na2S2O3
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