[kahlen]

its from may/june 07 igcse chemistry
can somebody plz explain me how to calculate moles of iodine molecules???

A better way of measuring the degree of unsaturation is to find the iodine number of the unsaturated compound. This is the mass of iodine that reacts with all the double bonds in 100g of the fat.

use the following info to calculate the number of double bonds in one molecule of the fat.

Mass of one mole of the fat is 884g
one mole of iodine molecule reacts with one mole of carbon double bond.
The iodine number of the fat is 86.2g
100g of the fat reacts with 86.2g of iodine.
884g of the fat reacts with 762g of iodine
One mole of fat reacts with _________moles of iodine molecules

The answer for the blank is 762 divided by 254 but i have no idea where the number 254 comes from???
can somebody explain me???

[Borek]

How do you convert mass of the substance to number of moles of the substance?

For example - 64 grams of oxygen, how many moles?

[richie4]

either 4 moles 0 or 2 moles 02