Two isomers (A) and (B) with Molar mass 184 g/mol and elemental composition C, 52.2%; H, 4.9% and Br 42.9% gave benzoic acid and p-bromobenzoic acid, respectively on oxidation with KMnO₄. Isomer 'A' is optically active and gives a pale yellow precipitate when warmed with alcoholic AgNO₃. Isomer 'A' and 'B' are, respectively

In Friedel-Crafts alkylation of aniline, one gets

The structure of protein that is unaffected by heating is

A white precipitate was formed when BaCl₂ was added to water extract of an inorganic salt. Further, a gas 'X' with characteristic odour was released when the formed white precipitate was dissolved in dilute HCl. The anion present in the inorganic salt is