A ' p '-block element ( E ) and hydrogen form a binary cation ( EH _ x )⁺ , while EH ₃ on treatment with K ₂ HgI ₄ in alkaline medium gives a precipitate of basic mercury(II)amido-iodine. Given below are first ionisation enthalpy values ( kJ mol ⁻¹ ) for first element each from group 13, 14, 15 and 16. Identify the correct first ionisation enthalpy value for element E.

Step-by-step solution

The p-block element E forms a binary cation (EH_x)^+ with hydrogen and produces a basic mercury(II) amido-iodide precipitate with K₂HgI₄ in alkaline medium. This behavior is characteristic of ammonia (NH₃), which forms the ammonium ion (NH₄)^+ and reacts with Nessler's reagent ( K₂HgI₄ ) to form a characteristic brown/yellow precipitate. Therefore, E is Nitrogen (N), a Group 15 p-block element with electronic configuration 1s^2 2s^2 2p^3 . Nitrogen has a notably high first ionization enthalpy compared to other grou