Use the standard reduction potentials to determine what is observed at the cathode during the electrolysis of a 1.0M solution of \ce{KBr} that contains phenolphthalein. What observation(s) is(are) made?\ce{O2 (g)} + \ce{4H^+ (aq)} + 4e^- \rightarrow \ce{2H2O (l) }; \text{ E}^\circ = \text{1.23 V}
\ce{Br2 (l)} + 2e^- \rightarrow \ce{2Br^- (aq)} ; \text{ E}^\circ = \text{1.07 V}
\ce{2H2O (l)} + 2e^- \rightarrow \ce{H2 (g)} + \ce{2OH^-} ; \text{ E}^\circ = \text{-0.80 V}
\ce{K^+ (aq)} + e^- \rightarrow \ce{K (s)} ; \text{ E}^\circ = \text{-2.92 V}
<spanclass=′latex−bold′>(A)</span>Solid metal forms<spanclass=′latex−bold′>(B)</span>Bubbles form and a pink color appears(C) \text{Dark red } \ce{ Br2} \text{ forms}\qquad<spanclass=′latex−bold′>(D)</span>Bubbles form and the solution remains colorless