ECAT Chemistry — p-Block Elements
p-Block Elements is part of the Chemistry section of the UET ECAT (30 of the 100 MCQs). It breaks into 4 subtopics, and we hold 34 ECAT-pattern practice MCQs on it, each with a written explanation. Tap a subtopic below to practise just that.
Subtopics (4)
How p-Block Elements is tested
Across the 7 ECAT past papers on ParhaiKrlo, p-Block Elements accounts for 15 questions. It appears in 6 of them, about 2.5 questions a paper. The heaviest was ECAT Past Paper 05, with 4 questions, and the most recent is ECAT Past Paper 07, with 2.
| Paper | Questions |
|---|---|
| ECAT Past Paper 07 | 2 |
| ECAT Past Paper 06 | 3 |
| ECAT Past Paper 05 | 4 |
| ECAT Past Paper 04 | 1 |
| ECAT Past Paper 02 | 2 |
| ECAT Past Paper 01 | 3 |
p-Block Elements MCQs from the ECAT past papers
Try each one before opening the answer. Each comes with a short explanation.
- Q1 · ECAT Past Paper 07 · p-Block Elements
Quartz has a tetrahedral network of silicon and oxygen atoms. How many silicon atoms are bonded to each oxygen atom?
- A.4
- B.3
- C.2
- D.1
Show answer
Answer: C. 2 — Each Si is bonded to 4 O, and each O bridges 2 Si (giving SiO₂).
- Q2 · ECAT Past Paper 06 · p-Block Elements
Noble gases are chemically inert mainly because they have:
- A.Very low ionization energies
- B.Completely filled valence shells
- C.High electronegativities
- D.Large atomic masses
Show answer
Answer: B. Completely filled valence shells — Their ns² np⁶ (He: 1s²) outer shells are complete and very stable, so they neither lose nor gain electrons easily.
- Q3 · ECAT Past Paper 05 · p-Block Elements
Which of the following oxides is unlikely to dissolve in sodium hydroxide?
- A.Al₂O₃
- B.MgO
- C.SiO₂
- D.NO₂
Show answer
Answer: B. MgO — MgO is a basic oxide and does not react with alkali; Al₂O₃ (amphoteric), SiO₂ and NO₂ (acidic) all react with NaOH.