9. Hydricarbon — Chemistry STD 11 Science — Question

$(ii)\, F_{(g)} + e^- \to F^-_{(g)}, \Delta H_2$

$(iii)\, Cl_{(g)} + e^- \to Cl_{(g)}, \Delta H_3$

$(iv)\, O_{(g)}^- + e^- \to O_{(g)}^{2-} , \Delta H_4$
That according to given information the incorrect statement is

Assertion $A$ :Phenolphthalein is a $pH$ dependent indicator, remains colourless in acidic solution and gives pink colour in basic medium

Reason $R$ : Phenolphthalein is a weak acid. It doesn't dissociate in basic medium.

In the light of the above statements, choose the most appropriate answer from the options given below.