Practise 22 real Federal Board questions on Acids, Bases and Salts from 2023 to 2025. See the answer and explanation as soon as you answer.
Acids, Bases and Salts is one of the 11 main chapters in our Federal Board Matric Chemistry question bank (10th class), and about 6% of its real questions come from it. Tayyari Karo has 22 real questions on this chapter from 2023 to 2025; 8 are multiple choice and marked instantly, and the rest are short and long questions with a model answer. By difficulty: 16 medium, 6 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 behave both as Bronsted acid and Bronsted base?
Answer: B. H₂O
Water is amphiprotic — it can donate a proton (act as acid, forming OH⁻) or accept a proton (act as base, forming H₃O⁺).
Identify the Arrhenius base:
Answer: B. NaOH
NaOH directly dissociates in water to give OH⁻ ions, the defining feature of an Arrhenius base.
Which of the following is classified as an Arrhenius base?
Answer: C. NaOH
NaOH directly dissociates in water to give OH⁻ ions, the defining feature of an Arrhenius base.
Which solution turns blue litmus paper red?
Answer: B. Vinegar
Vinegar (dilute acetic acid) is acidic and turns blue litmus paper red; soap, baking soda and detergent are basic/alkaline.
Complete the reaction: H₂CO₃ + 2NaOH → ________ + 2H₂O
Answer: A. Na₂CO₃
This is a neutralization reaction; balancing Na and C atoms gives sodium carbonate, Na₂CO₃, as the salt product.
Identify Lewis base from the following:
Answer: B. Cl¹⁻
A Lewis base donates an electron pair. Cl⁻ has lone pairs available to donate; HCl, AlCl₃ and BF₃ are electron-pair acceptors (Lewis acids) or neutral molecules.
Classify the following as Lewis acid or Lewis base: (a) H₂O (b) Br⁻ (c) Cu⁺² (d) NH₃ (e) Fe⁺³ (f) BF₃
Lewis acids (electron-pair acceptors): (c) Cu²⁺, (e) Fe³⁺, (f) BF₃ — these have empty orbitals or a positive charge that can accept an electron pair.
Lewis bases (electron-pair donors): (a) H₂O, (b) Br⁻, (d) NH₃ — these have lone pairs of electrons available to donate.
What are Lewis acids and bases? How do they differ from Bronsted-Lowry acids and bases? Give example of each.
Lewis acid: a substance that can accept an electron pair (has an empty orbital), e.g. BF₃, Al³⁺.
Lewis base: a substance that can donate an electron pair (has a lone pair), e.g. NH₃, Cl⁻.
Difference from Bronsted-Lowry: The Bronsted-Lowry theory defines acids and bases specifically in terms of proton (H⁺) transfer — acid = proton donor, base = proton acceptor. The Lewis theory is broader: it defines acids/bases in terms of electron-pair transfer, which also includes species that do not involve protons at all (e.g. BF₃, which has no H to donate, is still a Lewis acid because it accepts an electron pair). …
The full model answer is in the app.
| Session | Questions |
|---|---|
| 2025 1st Annual | 6 |
| 2025 2nd Annual | 6 |
| 2024 Annual | 5 |
| 2023 Annual | 5 |
22 real Federal Board (FBISE) Chemistry questions on Acids, Bases and Salts from 2023 to 2025, for 10th 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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