JEE Main · Chemistry ↑ Rising

p-Block Elements appeared 43 times across 3 years — 5% of Chemistry. This question is from Group 15 Hydrides.

Year 2026 2025 2024 Total
Questions 16 14 13 43
Practice all p-Block Elements questions → View full JEE Main weightage & trends →

Choose the correct statements about the hydrides of group 15 elements. A. The stability of the hydrides decreases in the order NH₃ > PH₃ > AsH₃ > SbH₃ > BiH₃ B. The reducing ability of the hydrides increases in the order NH₃ < PH₃ < AsH₃ < SbH₃ < BiH₃ C. Among the hydrides, NH₃ is strong reducing agent while BiH₃ is mild reducing agent. D. The basicity of the hydrides increases in the order NH₃ < PH₃ < AsH₃ < SbH₃ < BiH₃ Choose the most appropriate from the option given below:

Solution & Explanation

Core Logic

Statement A: As we move down Group 15, the size of the central atom increases, causing the E-H bond length to increase and its bond strength to decrease. Thus, thermal stability decreases in the order: NH₃ > PH₃ > AsH₃ > SbH₃ > BiH₃. Statement A is correct.

Statement B: Because the E-H bond strength decreases down the group, it becomes easier to release hydrogen. Therefore, the reducing ability increases down the group: NH₃ < PH₃ < AsH₃ < SbH₃ < BiH₃. Statement B is correct.

Statement C: Following the logic from B, NH₃ is a very weak reducing agent (mild), while BiH₃ is the strongest reducing agent among them. Statement C is false.

Statement D: Basicity depends on the availability of the lone pair for donation. In NH₃, the lone pair is concentrated in a small sp³ orbital (high electron density). Moving down the group, the lone pair occupies larger orbitals with more s-character (Drago's rule), decreasing electron density and making the lone pair less available. Thus, basicity decreases down the group. Statement D is false.

Step 1: Final Conclusion

Only statements A and B are correct.

Chapter Mix

Class 12 Chemistry: The p Block Elements

Reference Study Guides

The P Block Elements

More The p Block Elements Previous-Year Questions — Page 9

Q64 jee_main_2024_31_jan_evening Properties of Sulphur and Halogens
Given below are two statements: Statement I: S₈ solid undergoes disproportionation reaction under alkaline conditions to form S²⁻ and S₂O₃²⁻ Statement II: ClO₄^- can undergo disproportionation reaction under acidic condition. In the light of the above statements, choose the most appropriate answer from the options given below:
  • A. Statement I is correct but statement II is incorrect.
  • B. Statement I is incorrect but statement II is correct
  • C. Both statement I and statement II are incorrect.
  • D. Both statement I and statement II are correct.

Solution

Core Logic

Statement I: S₈ disproportionates in alkaline medium to give sulphide (S²⁻) and thiosulphate (S₂O₃²⁻). The reaction is:

S₈ + 12OH^- arrow 4S²⁻ + 2S₂O₃²⁻ + 6H₂O

This is a correct statement.

Statement II: ClO₄^- contains chlorine in its highest possible oxidation state of +7. A species can undergo disproportionation only if the element can exist in both higher and lower oxidation states than the present one. Since chlorine cannot exceed +7, ClO₄^- cannot undergo disproportionation. This is an incorrect statement.

Step 1: Final Conclusion

Statement I is correct, and Statement II is incorrect. Therefore, option (1) is the correct answer.

Chapter Mix

Class 11 Chemistry: Redox Reactions Class 12 Chemistry: The p-Block Elements

Q61 jee_main_2024_31_jan_morning Group 18 Elements
Give below are two statements: Statement-I: Noble gases have very high boiling points. Statement-II: Noble gases are monoatomic gases. They are held together by strong dispersion forces. Because of this they are liquefied at very low temperature. Hence, they have very high boiling points. In the light of the above statements, choose the correct answer from the options given below:
  • A. Statement I is false but Statement II is true.
  • B. Both Statement I and Statement II are true.
  • C. Statement I is true but Statement II is false.
  • D. Both Statement I and Statement II are false.

Solution

Core Logic

Statement I and II are False.

Noble gases have low boiling points. Noble gases are held together by weak dispersion forces.

Pattern Recognition

Noble gases are characterized by extremely weak intermolecular forces (London dispersion forces) because they are monoatomic and non-polar, which directly results in very low boiling and melting points.

Chapter Mix

Class 12 Chemistry: The p-Block Elements

Q79 jee_main_2024_31_jan_morning Group 14 Elements
Consider the oxides of group 14 elements SiO₂, GeO₂, SnO₂, PbO₂, CO and GeO. The amphoteric oxides are
  • A. GeO, GeO₂
  • B. SiO₂, GeO₂
  • C. SnO₂, PbO₂
  • D. SnO₂, CO

Solution

Core Logic

In Group 14 elements, the nature of oxides varies down the group: CO is neutral. CO₂ and SiO₂ are acidic. GeO₂ is distinctly acidic. SnO₂ and PbO₂ are amphoteric.

Pattern Recognition

Tin (Sn) and Lead (Pb) mostly form amphoteric oxides (e.g., SnO, SnO₂, PbO, PbO₂), distinguishing them from the acidic oxides of Carbon and Silicon.

Chapter Mix

Class 11 Chemistry: The p-Block Elements

More The p Block Elements Questions — jee_main_2024_30_january_evening

Practice all The p Block Elements previous-year questions →

Rankbit System
JEE Physics: Waves (+15.5%) | Electrostatics: Concentric Shells (-29.7%) | Modern Physics: Photoelectric Clones (+34.2%) | Mathematics: Definite Integrals (+18.1%) | Chemistry: Coordination Splitting (-11.4%) | JEE Physics: Waves (+15.5%) | Electrostatics: Concentric Shells (-29.7%) | Modern Physics: Photoelectric Clones (+34.2%) | Mathematics: Definite Integrals (+18.1%) | Chemistry: Coordination Splitting (-11.4%)