JEE Advanced levelOne or more correct optionsDifficulty 3 of 3rx159
Use K = 39, I = 127, O = 16. 0.01 mol of KIOX3 reacts with excess KI in acid: IOX3X−+5IX−+6HX+3IX2+3HX2O. Select the correct statement(s).
A0.03 mol of IX2 is liberated
BThe IX2 requires 0.06 mol of SX2OX3X2− for titration (to tetrathionate)
CThe equivalent mass of KIOX3 in this reaction is 42.8
DThe mass of IX2 liberated is 2.54g
Answer: A, B, C
IX2=3×0.01=0.03 mol (A true); thiosulfate =2×0.03=0.06 mol (B true). IOX3X− (+5→0) has n=5 and M=214, so equivalent mass =42.8 (C true). Mass of IX2=0.03×254=7.62g, not 2.54 (D false).