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NEET p-Block Elements: 5 practice MCQs with answers

By the PrepMatic team · Updated 9 Oct 2026 · 3 min read

The p-block is the largest inorganic section of NEET Chemistry, spanning Groups 13 to 18 from boron to the noble gases. Questions are factual: properties, reactions, structures and uses straight from NCERT. The five MCQs below cover boric acid, nitric acid, the contact process, oxoacids of chlorine and the shape of XeF₄.

What this chapter covers in the NEET syllabus

The NMC unit is p-Block Elements, covering Groups 13 to 18. NCERT splits it across Class 11 (Groups 13 and 14) and Class 12 (Groups 15 to 18). The topics are:

• General trends in electronic configuration, atomic radius, ionisation enthalpy, electronegativity and oxidation states across periods and down groups, the unique behaviour of the first element in each group, and the inert pair effect.
• Group 13 and 14: boron and aluminium compounds, allotropes of carbon, silicon compounds and silicones.
• Group 15: nitrogen, ammonia, oxides of nitrogen, nitric acid, phosphorus and its compounds.
• Group 16: oxygen, ozone, sulphur, sulphur dioxide and sulphuric acid.
• Group 17: halogens, hydrogen halides, oxoacids and interhalogen compounds.
• Group 18: noble gases and compounds of xenon.

Five practice MCQs on the p-Block

Question 1

Boric acid, B(OH)₃, acts in water as:

• A. a tribasic Brønsted acid
• B. a Lewis acid
• C. a Lewis base
• D. a strong acid

Question 2

Copper reacts with dilute nitric acid to produce mainly:

• A. NO
• B. NO₂
• C. N₂O
• D. NH₃

Question 3

The catalyst used in the contact process for the manufacture of sulphuric acid is:

• A. Fe
• B. Pt-Rh gauze
• C. Ni
• D. V₂O₅

Question 4

Among the oxoacids of chlorine, the strongest acid is:

• A. HClO₄
• B. HOCl
• C. HClO₃
• D. HClO₂

Question 5

The shape of the XeF₄ molecule is:

• A. tetrahedral
• B. square planar
• C. see-saw
• D. octahedral

Answers and explanations

1. B. Boric acid is not a proton donor in the usual sense. It accepts a hydroxide ion from water, forming [B(OH)₄]⁻ and releasing H⁺, which makes it a weak monobasic Lewis acid. Boron has an incomplete octet, so it is electron deficient.
2. A. With dilute HNO₃, copper gives nitric oxide: 3Cu + 8HNO₃ → 3Cu(NO₃)₂ + 2NO + 4H₂O. With concentrated nitric acid the product is NO₂ instead.
3. D. The contact process oxidises SO₂ to SO₃ over vanadium(V) oxide, V₂O₅, at about 2 bar and 720 K. Iron is the catalyst in the Haber process, and platinum-rhodium gauze is used in the Ostwald process.
4. A. In the series HOCl, HClO₂, HClO₃ and HClO₄, acid strength rises with the oxidation state of chlorine and the number of oxygen atoms, which stabilise the anion. HClO₄ is the strongest.
5. B. Xenon in XeF₄ has four bond pairs and two lone pairs, six electron pairs in all. The lone pairs sit opposite each other, so the molecule is square planar with sp³d² hybridisation.

How to prepare the p-Block

• Organise by group, not by chapter order. For each group make a one-page sheet: trend in properties, anomalous behaviour of the first element, important compounds, reactions, structures and uses. Revise one sheet a day.
• Learn structures and shapes together. Draw H₃PO₃ and H₃PO₂ (and count P-H and P-OH bonds), the structure of ozone, SO₂, H₂SO₄, and the interhalogens. Many questions ask for the number of bonds or lone pairs.
• Link reactions to conditions. Dilute versus concentrated, hot versus cold, and what each reagent does. The reactions of HNO₃ with metals and non-metals, of Cl₂ with hot or cold alkali, and of SO₂ are favourites.
• Memorise trends with their reasons. Why is nitrogen unreactive, why does boron form covalent compounds, why is HF a weak acid but the strongest hydrogen-bonded one, why does the stability of the +2 state increase down Group 14?
• Use NCERT text first. NCERT lines on uses, colours, odours and manufacture are the usual source of questions in this unit.

Because so much is factual, short daily revision beats one long session. See the NEET Chemistry preparation guide for how to split time between physical, organic and inorganic, and NCERT for NEET for how to read each line.

Take a full p-Block Elements test on PrepMatic

Because the p-block is memory-heavy, spaced testing helps more than a single big revision. PrepMatic's study plan turns your exam date and daily hours into a month-by-week roadmap, with topic tests as checkpoints on what you have finished. A topic test is about 15 questions in 30 minutes, and more chapters are on the practice hub.

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