Acids, Bases and Salts — Class 10 MCQs with Answers
Class 10 CBSE Science (Chemistry) · Chapter 2
90 practice questions · 30 Easy · 30 Medium · 30 Hard · Updated
Practise the most important Class 10 CBSE Science (Chemistry) questions from Chapter 2, "Acids, Bases and Salts". You get 9 timed quizzes made from 90 NCERT-based MCQs, with answers and explanations. The questions are split into 30 Easy, 30 Medium and 30 Hard. Warm up on the basics, then move on to the exam-level questions that set top scorers in CBSE Board exams and the JEE & NEET foundation years apart.
To score well in "Acids, Bases and Salts", focus on clear concepts in physics, chemistry and biology basics. Each MCQ here is timed and uses exam-style marking (+4 correct, −1 wrong, 0 skipped). This trains you to stay accurate under time pressure, as real papers need. Every question has a short explanation, so a wrong answer becomes a quick lesson. It is the fastest way to fix gaps before a test.
Use this chapter for focused revision. Start with the Easy set to check your basics on Acids, Bases and Salts, then move to Medium and Hard to practise applying them. Your accuracy, streaks and XP save automatically. This chapter also adds to your overall Class 10 Science (Chemistry) mastery score. 14 sample questions are solved in full below, with the answer and a worked explanation. Sign in free to start practising.
Key concepts: Acids, Bases and Salts (Class 10 Science (Chemistry))
Acids give hydrogen ions in water and bases give hydroxide ions, and the pH scale measures how many. This chapter covers indicators, neutralisation, the reactions of acids and bases, and the preparation and uses of important salts.
- Acid
- A substance that produces hydrogen ions (H⁺) in aqueous solution, tastes sour and turns blue litmus red.
- Base and alkali
- A base produces hydroxide ions (OH⁻) and turns red litmus blue; an alkali is simply a base that dissolves in water.
- Indicator
- A substance that changes colour with acidity — litmus, methyl orange and phenolphthalein are the common ones.
- Olfactory indicator
- A substance whose SMELL changes in acid or base, such as onion or vanilla essence, used to test solutions without sight.
Acids, Bases and Salts — important questions & MCQs with answers (Class 10 Science (Chemistry))
14 solved questions from this chapter's difficulty levels, each with its answer and explanation. The other 76 are timed and scored when you sign in.
- Q1Easy
The pH of a neutral solution is:
A.0B.7✓ CorrectC.10D.14Answer: B. 7
Explanation: On the 0–14 pH scale, 7 is neutral. <7 acidic, >7 basic.
- Q2Easy
Acid + active metal usually produces:
A.Salt + hydrogen gas✓ CorrectB.Salt + waterC.Salt + oxygenD.Only waterAnswer: A. Salt + hydrogen gas
Explanation: Metal + acid → salt + hydrogen gas, e.g. Zn + 2 HCl → ZnCl₂ + H₂↑; oxygen or plain water are not the typical products of this reaction.
- Q3Easy
Blue litmus turns red in:
A.Acid✓ CorrectB.BaseC.Neutral solutionD.WaterAnswer: A. Acid
Explanation: H⁺ ions from an acid turn blue litmus paper red; the same paper stays blue in a base and shows no colour change in neutral water.
- Q4Easy
Common salt is chemically:
A.NaOHB.Na₂CO₃C.NaHCO₃D.NaCl✓ CorrectAnswer: D. NaCl
Explanation: Common salt is sodium chloride, NaCl, formed by neutralising HCl with NaOH — distinct from NaOH (a base), Na₂CO₃ (washing soda) or NaHCO₃ (baking soda).
- Q5Easy
A strong acid:
A.Fully ionises in water✓ CorrectB.Partially ionisesC.Does not ioniseD.Decomposes waterAnswer: A. Fully ionises in water
Explanation: A strong acid ionises completely in water, releasing the maximum H⁺ per molecule; a weak acid only partially ionises, giving a higher pH at the same concentration.
- Q6Easy
Reaction between an acid and a base is called:
A.CombustionB.DisplacementC.CombinationD.Neutralisation✓ CorrectAnswer: D. Neutralisation
Explanation: An acid reacting with a base to give salt and water is called neutralisation — distinct from combustion, displacement or simple combination reactions.
- Q7Medium
Which has the lowest pH?
A.Lemon juice✓ CorrectB.Tap waterC.Milk of magnesiaD.Soap solutionAnswer: A. Lemon juice
Explanation: Lemon juice contains citric acid and has pH ≈ 2, well below tap water (~7), soap solution (~9–10) and milk of magnesia (~10) — the lowest pH is the most acidic.
- Q8Medium
What products form when HCl reacts with NaOH?
A.NaOH₂ + Cl₂B.NaCl + H₂O✓ CorrectC.Na₂Cl + H₂OD.NaH + ClOAnswer: B. NaCl + H₂O
Explanation: Acid + base → salt + water (neutralisation). HCl + NaOH → NaCl + H₂O.
- Q9Medium
Onion paste is an example of:
A.pH paperB.Olfactory indicator✓ CorrectC.LitmusD.Universal indicatorAnswer: B. Olfactory indicator
Explanation: Onion paste loses its odour in basic solutions — an olfactory indicator signals acids or bases by a change in smell.
- Q10Medium
Plaster of Paris is chemically:
A.Ca(OH)₂B.CaSO₄·2H₂OC.CaCO₃D.CaSO₄·½H₂O✓ CorrectAnswer: D. CaSO₄·½H₂O
Explanation: Plaster of Paris is calcium sulphate hemihydrate, CaSO₄·½H₂O.
- Q11Medium
Acids show acidic behaviour only when:
A.FrozenB.HeatedC.DryD.Dissolved in water (release H⁺)✓ CorrectAnswer: D. Dissolved in water (release H⁺)
Explanation: An acid shows its acidic behaviour only when dissolved in water, since ionisation releases the H⁺ ions responsible for acidity — a dry or frozen acid does not ionise.
- Q12Hard
When water is added to a concentrated acid, what happens to the H⁺ ion concentration and pH?
A.[H⁺] increases; pH increasesB.[H⁺] increases; pH decreasesC.Both unchangedD.[H⁺] decreases; pH increases✓ CorrectAnswer: D. [H⁺] decreases; pH increases
Explanation: Dilution lowers H⁺ concentration; pH = −log[H⁺] therefore rises (toward 7).
- Q13Hard
When dilute H₂SO₄ reacts with iron, the gas evolved makes pop sound with burning splinter. The gas is:
A.H₂✓ CorrectB.O₂C.SO₂D.CO₂Answer: A. H₂
Explanation: Fe + dilute H₂SO₄ → FeSO₄ + H₂; the hydrogen gas gives the characteristic 'pop' with a burning splinter.
- Q14Hard
The letter p in the term pH stands for:
A.PositiveB.Potenz, the German word for power✓ CorrectC.ProtonD.PercentageAnswer: B. Potenz, the German word for power
Explanation: The p in pH stands for 'potenz' in German, meaning power.
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Start this chapter free →Acids, Bases and Salts — FAQs
What are the key concepts in Class 10 Science (Chemistry) Acids, Bases and Salts?+
Acids give hydrogen ions in water and bases give hydroxide ions, and the pH scale measures how many. This chapter covers indicators, neutralisation, the reactions of acids and bases, and the preparation and uses of important salts. Key ideas include Acid, Base and alkali, Indicator, Olfactory indicator.
What does Class 10 Science (Chemistry) Chapter 2 (Acids, Bases and Salts) cover on XamBaaz?+
It has 90 NCERT-based MCQs on "Acids, Bases and Salts": 30 Easy, 30 Medium and 30 Hard. Together they make 9 timed quizzes, and you never get the same set twice. Every question has an instant explanation. They help you prepare for CBSE Board exams and the JEE & NEET foundation years.
Are these "Acids, Bases and Salts" questions free to practise?+
Yes. Sign in with Google to practise "Acids, Bases and Salts" free. Full unlimited access is ₹999/year on a launch offer until 1 December 2026. No chapter is charged separately.
How should I revise "Acids, Bases and Salts" for the exam?+
Start with the Easy quiz to check your basics, then try Medium and Hard to practise applying them. There are 9 timed quizzes on this chapter, so you can come back for a fresh set instead of one you have seen. Read each explanation, retry the questions you miss, and track your accuracy until it stays high.
Are these "Acids, Bases and Salts" MCQs available with answers?+
Yes. 14 sample questions are shown here in full, each with the correct option and a step-by-step "Why" explanation. Sign in free with Google to start practising, with instant scoring.
Is there negative marking in the "Acids, Bases and Salts" quizzes?+
Yes. The timed quizzes use exam-style marking: +4 for a right answer, −1 for a wrong one and 0 for a skip. MHT-CET and CBSE board papers have no negative marking. Our mocks for those are scored their way.
What are the important questions from Acids, Bases and Salts (Class 10 Science (Chemistry))?+
The questions that matter most test Acid, Base and alkali, Indicator, Olfactory indicator. This page shows 14 solved important MCQs with answers and explanations; all 90 questions on the chapter are available as timed quizzes once you sign in.
Is there an online quiz for Acids, Bases and Salts?+
Yes — Class 10 Science (Chemistry) Acids, Bases and Salts has timed online quizzes at Easy, Medium and Hard levels, with instant scoring and a worked explanation on every question. The first quiz on the chapter is free.