Geo-Scientist Prelims 2021 Chemistry Q39: Consider following statements in respect of titration between Ca²⁺…

Consider following statements in respect of titration between Ca²⁺ solution and EDTA solution using Eriochrome Black T as indicator (In):

1. The end point will be red in color
2. The end point will be blue in color
3. The end point depends on pH of solution which is controlled by adding ammonia –ammonium citrate buffer
4. The end point is observed since metal–In complex is more stable than metal–EDTA complex

Which of the statement(s) given above is/are correct?

1. (a) 1, 3 and 4
2. (b) 2, 3 and 4
3. (c) 2 and 3 only
4. (d) 2 only