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Chemistry - p Block Elements (Group 15, 16, 17 & 18)

Practise 14 NEST (NISER) previous year questions on p Block Elements (Group 15, 16, 17 & 18), compiled from papers spanning 2012 to 2023. Each question is pulled directly from the actual exam paper it appeared in, so you're practising in the exact style and difficulty NEST (NISER) tests.

p Block Elements (Group 15, 16, 17 & 18) has been asked in 6 of the 16 years of NEST (NISER) papers analysed (2011–2026), with 14 questions in all. 7% of them were easy, 93% moderate and 0% tough. Most of its questions came from 2021, with 4 questions that year. In the last three years (2024–2026) it had 0 questions across 4 papers, about 0 per paper.

The chapter's 5 topics are not weighted equally: Nitrogen and Its Compounds (4 questions, 29%), Phosphorus and Its Compounds (4 questions, 29%), and Halogens and Its Compounds (3 questions, 21%) have been asked the most. Over the last five years the most frequent topics have been Phosphorus and Its Compounds (2) and Nitrogen and Its Compounds (1).

  1. 1Pyrophosphoric acid and pyrophosphorous acid are oxyacids of phosphorous. The number of P-OH bonds present in pyrophosphoric acid and pyroph2023 (Session 1)Phosphorus and Its Compounds
  2. 2Ammonium sulfate on reaction with sodium hydroxide produces compounds and R along with water. Catalytic oxidation of Q by atmospheric oxygen2023 (Session 2)Nitrogen and Its Compounds
  3. 3Hydrolysis of in the presence of moisture gives the compound along with fumes of HCl . On heating, disproportionates to give compound and ph2022 (Session 2)Phosphorus and Its Compounds
  4. 4reacts with to form an adduct . The shape/geometry around the Xe and Sb ions, in the adduct, are respectively2021 (Session 1)Noble Gases
  5. 5Peroxodisulphuric acid2021 (Session 1)Sulphur and Its Compounds
  6. 6Consider the following reactions (unbalanced) In the N -oxides ( and Z ), the oxidation state of nitrogen increases in the order2021 (Session 2)Nitrogen and Its Compounds
  7. 7Group 16 elements form hydrides of the type and . The correct statement regarding these hydrides is2021 (Session 2)Sulphur and Its Compounds
  8. 8Phosphorous forms different oxyacids such as, hypophosphorous acid , orthophosphorous acid and orthophosphoric acid . Orthophosphorous acid 2019 (Session 1)Phosphorus and Its Compounds
  9. 9When a mixture of NaCl , conc. and is heated, red vapours of compound are formed. These vapours dissolve in aqueous NaOH to form a yellow so2019 (Session 1)Halogens and Its Compounds
  10. 10Nitrogen is known to form a variety of oxides and oxyacids. NO and are unstable, while is a stable oxide. is a brown acidic gas at room temp2019 (Session 2)Nitrogen and Its Compounds
  11. 11Interhalogen compounds are formed when two halogens react together. They are represented by , where X is halogen of larger size and of small2019 (Session 2)Halogens and Its Compounds
  12. 12In and , the numbers of bonds are, respectively,2018Phosphorus and Its Compounds
  13. 13The correct order of acidity of the following compounds is2012Halogens and Its Compounds
  14. 14Which of the following pentachlorides does not exist?2012Nitrogen and Its Compounds

Frequently Asked Questions

1.How many questions are available for p Block Elements (Group 15, 16, 17 & 18)?

This chapter includes 14 questions compiled from NEST (NISER) papers spanning 2012 to 2023.

2.Are these questions only from NEST (NISER), or from other exams too?

These are NEST (NISER) questions specifically for the p Block Elements (Group 15, 16, 17 & 18) chapter. Questions from other exams like JEE Main or NTA Abhyas (JEE Main) are organised separately under their respective exam sections.

3.Is p Block Elements (Group 15, 16, 17 & 18) an important chapter for NEST (NISER) Chemistry?

p Block Elements (Group 15, 16, 17 & 18) has appeared in 6 of the 16 years of NEST (NISER) papers covered here, with 14 questions across 9 papers - about 2 per paper it appears in.

4.What is the difficulty level of p Block Elements (Group 15, 16, 17 & 18) questions in NEST (NISER)?

Of the 14 questions analysed for this chapter, 7% are easy, 93% moderate and 0% tough. 2021 had the most, with 4 questions.

5.Which topics in p Block Elements (Group 15, 16, 17 & 18) should I focus on?

These topics have carried the most weightage in p Block Elements (Group 15, 16, 17 & 18):

  • Nitrogen and Its Compounds - 4 questions (29%)
  • Phosphorus and Its Compounds - 4 questions (29%)
  • Halogens and Its Compounds - 3 questions (21%)
6.Is p Block Elements (Group 15, 16, 17 & 18)'s weightage in NEST (NISER) going up or down?

Across all 9 papers analysed, p Block Elements (Group 15, 16, 17 & 18) has averaged about 1.6 questions per paper. In the last three years (2024–2026), that average has fallen, at about 0.0 questions per paper. Use the year-wise numbers on this page for the exact trend before you decide how much time to give it.