The question asks for the general valence shell electronic configuration of Group 15 elements. To determine this, we need to recall the position of Group 15 in the periodic table and the rules for filling electron orbitals according to the Aufbau principle, Hund's rule, and Pauli exclusion principle.
A) ns²np³ — half-filled p-subshell giving extra stability. This option correctly identifies the valence shell electronic configuration as \( \text{ns}^2\text{np}^3 \) and accurately states that a half-filled p-subshell confers extra stability, which is a key characteristic of Group 15 elements.
The question asks why nitrogen does not form pentahalides (NX₅) while phosphorus does (PCl₅). This difference in behavior between elements of the same group (Group 15) is typically due to differences in their electronic configuration, particularly the availability of valence orbitals for bonding.
C) Nitrogen lacks d-orbitals in its valence shell (n=2 has only s and p orbitals), so it cannot expand its octet beyond 4 bonds; phosphorus (n=3) has available 3d orbitals to accommodate 5 bonds. This statement accurately explains the difference in bonding capacity between nitrogen and phosphorus, based on their electronic configurations and the availability of d-orbitals.
The question asks about the implications of the Inert Pair Effect on Group 15 elements. We need to understand what the Inert Pair Effect is and how it influences the oxidation states and properties of elements down a group, particularly for heavier elements.
Correct Option: D) The stability of +5 oxidation state decreases and +3 oxidation state increases down the group — the ns² electrons become increasingly reluctant to participate in bonding. This statement accurately describes the consequences of the inert pair effect in Group 15 elements.
The question asks to identify the only well-characterised Bismuth(V) compound, given that the stability of the +5 oxidation state decreases down Group 15. This phenomenon is due to the inert pair effect, which becomes more prominent for heavier elements in a group.
B) BiF₅ (bismuth pentafluoride) — Bismuth pentafluoride (\(\text{BiF}_5\)) is the only well-characterised and relatively stable compound of Bismuth in its +5 oxidation state. This is due to the high electronegativity and oxidizing power of fluorine, which helps to stabilize the higher oxidation state of Bismuth, overcoming the inert pair effect to some extent.
The question asks for laboratory methods to prepare dinitrogen (N₂). We need to identify the chemical reactions or processes suitable for laboratory-scale production of N₂.
C) Ammonium dichromate: \(\text{(NH}_4)_2\text{Cr}_2\text{O}_7 \rightarrow \text{N}_2 + \text{Cr}_2\text{O}_3 + 4\text{H}_2\text{O}\), or by heating ammonium nitrite solution: \(\text{NH}_4\text{Cl} + \text{NaNO}_2 \rightarrow \text{N}_2 + 2\text{H}_2\text{O} + \text{NaCl}\). Both reactions listed are standard laboratory methods for the preparation of dinitrogen gas.
The question asks to identify the correct reaction and conditions for the industrial manufacturing of ammonia (NH₃) via the Haber Process. We need to recall the balanced chemical equation, typical operating conditions (temperature, pressure), and catalysts used in this process.
B) \(\text{N}_2 + 3\text{H}_2 ightleftharpoons 2\text{NH}_3\) (conditions: 200 atm pressure, 700 K temperature, Fe catalyst with Mo as promoter)
This option accurately describes the Haber Process, including the balanced chemical equation, the reversible nature of the reaction, the typical high pressure (around 200 atmospheres), the optimal temperature (around 700 K or 400-450 °C), and the use of an iron catalyst with molybdenum as a promoter.