Amount of oxalic acid present in a solution can be determined by its titration with $$KMn{O_4}$$ solution in the presence of $${H_2}S{O_4}.$$ The titration gives unsatisfactory result when carried out in the presence of $$HCl,$$ because $$HCl$$ :

$$\alpha$$-D-(+)-glucose and $$\beta$$-D-(+)-glucose are

In which of the following octahedral complexes of Co (at. no. 27), will the magnitude of $$\Delta _o$$ be the highest?

Phenol, when it first reacts with concentrated sulphuric acid and then with concentrated nitric acid, gives