Practise 27 real Federal Board questions on Structure of Molecules from 2023 to 2026. See the answer and explanation as soon as you answer.
Structure of Molecules is one of the 11 main chapters in our Federal Board Matric Chemistry question bank (9th class), and about 8% of its real questions come from it. Tayyari Karo has 27 real questions on this chapter from 2023 to 2026; 9 are multiple choice and marked instantly, and the rest are short and long questions with a model answer. By difficulty: 15 medium, 12 easy.
Work through the questions below, then open the explanation for each one. Redo the ones you missed a few days later.
These are real past-paper questions. Think of your answer first, then open the explanation.
Which of the following can have more than one structural formula?
Answer: D. C₄H₈
C₄H₈ can exist as different structural isomers (e.g. 1-butene, 2-butene, isobutylene, cyclobutane), unlike the smaller alkanes listed which have only one possible structure.
Identify the covalent compound:
Answer: C. CH₄
CH₄ is formed between two non-metals (C and H) sharing electrons — a covalent compound. NaCl, CaO, NaF are ionic (metal + non-metal).
Identify the compound that is unsaturated:
Answer: B. CH≡CH
CH≡CH (acetylene) contains a carbon-carbon triple bond, making it unsaturated; the others contain only single bonds.
What type of bond is formed when two atoms share one or more pairs of electrons?
Answer: B. Covalent bond
A covalent bond is formed by the mutual sharing of one or more electron pairs between two atoms.
Which of the following is a saturated hydrocarbon?
Answer: D. CH₃−CH₃
CH₃−CH₃ (ethane) contains only single C–C and C–H bonds, making it saturated; the others contain double/triple bonds.
The functional group in amines is:
Answer: D. −NH₂
Amines are characterized by the amino functional group, −NH₂.
Show the following conversions by drawing their electron dot structures: (a) Na → Na⁺ (b) Cl → Cl⁻
(a) Na → Na⁺: Sodium atom (2,8,1) has 1 dot (valence electron) shown around its symbol; it loses this electron (shown removed) to form Na⁺ with no dots left in the valence shell (stable octet underneath, 2,8).
(b) Cl → Cl⁻: Chlorine atom (2,8,7) is shown with 7 dots around its symbol; it gains 1 more electron (shown as an added dot/cross) to complete its octet, forming Cl⁻ with 8 dots around it.
Draw the structural formula of C₄H₁₀. Is it a saturated hydrocarbon or unsaturated hydrocarbon?
Structural formula of C₄H₁₀ (n-butane): CH₃−CH₂−CH₂−CH₃ (a straight chain of 4 carbons, each carbon completing 4 bonds using single C–C and C–H bonds).
It is a saturated hydrocarbon, since it contains only single (C–C) bonds between carbon atoms, matching the general alkane formula CₙH₂ₙ₊₂.
| Session | Questions |
|---|---|
| 2026 Annual | 6 |
| 2025 1st Annual | 6 |
| 2025 2nd Annual | 7 |
| 2024 Annual | 5 |
| 2023 Annual | 3 |
27 real Federal Board (FBISE) Chemistry questions on Structure of Molecules from 2023 to 2026, for 9th class. Each one shows the session it came from.
No. We could not find an official FBISE marking scheme for these papers, so the answers and explanations are written by Tayyari Karo for practice. Check anything important with your teacher or textbook.
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