Spectrophotometric monitoring is not suitable to determine the end point of titration of:
(a)oxalic acid vs potassium permanganate
(b)iron(II) vs 1, 10-phenanthroline
(c)cobalt(II) vs Eriochrome black T
(d)nickel (II) vs dimethylglyoxime
Answer
Answer: C ✓ checked by 4AB · confidence medium
Explanation
Chapter key (c). Co(II) blocks Eriochrome Black T (the metal–indicator complex is too stable to release the dye), so no usable end-point colour change appears.