Acid Base Chemistry Test | Class 9 Chemistry
⚗️
🧪
💧
🔥

Acid Base Chemistry Test

Class 9th – Chemistry (SNC) – Chapter 7
2025@everexams.com
Paper Date:
Time: 60 minutes
Total Marks: 50
Paper Type: Objective + Subjective
Font Size:

Multiple Choice Questions 10×1=10

1 Which acid is used in the preparation of soap?
A Tartaric acid
B Citric acid
C Stearic acid
D Oxalic acid
2 Acetic acid is used for:
A Flavoring food
B Making explosives
C Etching designs
D Cleaning metals
3 Common name of sodium hydroxide is:
A Washing soda
B Baking soda
C Caustic soda
D None of these
4 Other name of stomach acidity?
A Hyperacidity
B Hypoacidity
C Both A and B
D None of these
5 Ammonia is a base because it:
A Ionizes in water to give OH⁻ ions
B Contains OH group
C Can accept proton
D None of these
6 What is the conjugate acid of NH₃?
NH3 + H+ ⇌ NH4+
A NH₄⁺
B NH₂⁻
C N₃H
D None of these
7 What is the conjugate base of HCl?
HCl ⇌ H+ + Cl
A Cl⁻
B H₂Cl⁺
C Cl₂
D None of these
8 Which of the following is a weak base according to the Bronsted Lowry theory?

Hint: Weak bases partially accept protons in solution

A NaOH
B HCl
C NH₃
D CH₃COOH
9 Which of the following acids is a strong acid?
Strong Bases Strong Acids
A Acetic acid
B Hydrochloric acid
C Citric acid
D Lactic acid
10 Which physical property distinguishes strong base from weak bases?
A pH
B Conductivity
C Viscosity
D Density

Short Answer Questions 15×2=30

1 What chemical name will you give to soap as a compound?
ii What is the difference between a strong acid and a concentrated acid? (Constructed Response Question)
iii How does calcium metal react with dilute H₂SO₄?
Ca + H2SO4 ?
iv Write down difference between acids and bases.
v Why metal oxides are bases in nature?
vi Difference between mineral acids and natural acids?
vii Name some compounds that contain citric acids?
viii Define Arrhenius acid. Also give example.
ix Define acid according to the Bronsted-Lowry theory.
x What is difference between conjugate acid and conjugate base?
HA ⇌ H+ + A
Acid ⇌ Proton + Conjugate Base
xi What is meant by amphoteric compounds?
xii What are limitations of Bronsted Lowry concept?
xiii How salt and water is produced during a chemical reaction?
Acid + Base Salt + Water
xiv How do chloride ions exist in water? Exercise
xv Give two examples of Bronsted-Lowry bases which are not bases by Arrhenius definition. Exercise

Hint: Consider substances that can accept protons but don’t produce OH⁻ ions in water

Detailed Answer Questions (Answer any 2) 2×5=10

1 Explain Arrhenius concept of acids and bases.

Key Points: – Acid: Substance that produces H⁺ ions in aqueous solution
– Base: Substance that produces OH⁻ ions in aqueous solution
– Examples: HCl, NaOH, H₂SO₄, KOH

HCl → H+ + Cl
NaOH → Na+ + OH
2 Briefly explain the concept of Bronsted-Lowry theory.

Key Concepts:
1. Acid: Proton donor (H⁺ donor)
2. Base: Proton acceptor (H⁺ acceptor)
3. Conjugate acid-base pairs
4. Amphoteric substances

NH3 + H2O ⇌ NH4+ + OH
Base₁ + Acid₂ ⇌ Acid₁ + Base₂
3 How does sulphuric acid react with NH₄NO₃, MgO, MgCO₃, NH₄Cl?

Reaction Types:
1. Acid + Salt → New Acid + New Salt
2. Acid + Metal Oxide → Salt + Water
3. Acid + Metal Carbonate → Salt + Water + CO₂
4. Acid + Ammonium Salt → New Salt + NH₃