JEE Advanced levelSingle correct optionDifficulty 3 of 3ph102
0.10 mol of KI in water is treated with just enough chlorine to convert all the iodide into KIOX3 (chlorine is reduced to ClX−). The number of moles of ClX2 required is
A0.60
B0.30
C0.10
D0.05
Answer: B
Iodine goes from -1 in IX− to +5 in IOX3X−, a loss of 6 electrons per iodide, i.e. 0.60 mol electrons for 0.10 mol KI. Each ClX2 accepts 2 electrons, so 0.60/2=0.30 mol ClX2. (KI+3ClX2+3HX2OKIOX3+6HCl.)