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Friday, 9 October

NEET UG 2021 · Chemistry · Question 100

NEET 2021 Chemistry, question 100

Question 100 of the NEET 2021 paper (code O1) is a Chemistry question from The p-Block Elements (Class 12). Its idea, Trends in Groups 15 to 18, was asked 4 times, in 2018, 2021 and 2024, across NEET 2017–2026. The NTA final answer key gives option 4.

Updated 2026-10-08

Q100 · Chemistry

In which one of the following arrangements the given sequence is not strictly according to the properties indicated against it ?

  1. 1NH3<PH3<AsH3<SbH3\mathrm{NH_3 < PH_3 < AsH_3 < SbH_3} : Increasing acidic character
  2. 2CO2<SiO2<SnO2<PbO2\mathrm{CO_2 < SiO_2 < SnO_2 < PbO_2} : Increasing oxidizing power
  3. 3HF<HCl<HBr<HI\mathrm{HF < HCl < HBr < HI} : Increasing acidic strength
  4. 4H2O<H2S<H2Se<H2Te\mathrm{H_2O < H_2S < H_2Se < H_2Te} : Increasing pKa\mathrm{pK_a} valuesOfficial answer

Official answer: option 4 · NTA final answer key

Same idea

Trends in Groups 15 to 18, in other papers

NEET asked this idea 4 times, in 2018, 2021 and 2024. The other 3 questions below.

  • 2024 Q72Among Group 16 elements, which one does NOT show −2-2 oxidation state?One-line MCQ · Easy
  • 2021 Q73Statement I : Acid strength increases in the order given as HF << HCl << HBr << HI. Statement II : As the size of the elements F, Cl, Br,…Two statements · Easy
  • 2018 Q50Which of the following statements is not true for halogens ?One-line MCQ · Medium

Trends in Groups 15 to 18: every question and how it was framed

The chapter

The p-Block Elements (Class 12) in ten years of NEET

23 questions from 2017–2026, asked in 10 of 10 papers, about 2.2 a paper. p-Block Elements (Groups 15-18) alone had 23.

Chapter analysis

The p-Block Elements (Class 12): questions per paper

0363’171’185’192’203’212’222’232’242’251’26