1 Which pair is a conjugate acid-base pair? A HCl and NaOH B CH₃COOH and CH₃COO⁻ C H₂O and NaCl D NH₃ and HCl
2 According to the Brønsted-Lowry concept, an acid is a: A Proton acceptor B Proton donor C Electron pair acceptor D Electron pair donor
3 Which of the following is an example of a strong acid? A Acetic acid (CH3COOH) B Carbonic acid (H2CO3) C Hydrochloric acid (HCl) D Water (H2O)
4 Water is called amphoteric because it can: A Only donate protons B Only accept protons C Both donate and accept protons D Neither donate nor accept protons
5 Water acts as both an acid and a base. This property of water is called: A Neutralisation B Amphoteric nature C Hydrolysis D Ionisation
6 Which safety rule should be followed when handling acids and bases in the laboratory? A Taste the solution to identify it B Wear safety goggles and gloves C Smell the gas directly D Store acids in open bottles
7 A limitation of the Arrhenius concept is that it: A Cannot explain the basic nature of ammonia B Cannot explain acids in water C Requires a non-aqueous solvent D Only applies to strong acids
8 According to the Brønsted-Lowry concept, what is an acid? A A proton donor B A proton acceptor C An electron pair donor D An electron pair acceptor
9 What is the conjugate base of H2O in the reaction: H2O + NH3 ⇌ NH4+ + OH−? A NH3 B NH4+ C OH− D H2O
10 According to the Lewis concept, a base is a substance that: A Donates a proton B Accepts a proton C Donates an electron pair D Accepts an electron pair
11 Which indicator is colourless in acidic solution and pink in basic solution? A Litmus B Phenolphthalein C Methyl orange D Red cabbage indicator
12 When an acid reacts with a metal, the gas usually produced is: A Carbon dioxide B Oxygen C Hydrogen D Sulfur dioxide
13 Ammonia (NH3) acts as a base according to Brønsted-Lowry by: A Accepting a proton B Donating a proton C Donating an electron pair D Accepting an electron pair
14 According to Lewis concept, a base is a: A proton donor B proton acceptor C electron-pair acceptor D electron-pair donor
15 Which concept defines an acid as an electron pair acceptor? A Arrhenius concept B Brønsted-Lowry concept C Lewis concept D Ostwald concept
16 What is formed when an acid reacts with a base? A Salt and water B Salt and hydrogen C Salt and carbon dioxide D Only water
17 Which concept describes an acid as an electron-pair acceptor? A Arrhenius concept B Brønsted-Lowry concept C Lewis concept D Ostwald concept
18 Which indicator turns red in acidic solution and yellow in basic solution? A Litmus B Phenolphthalein C Methyl orange D Universal indicator
19 Which of the following is a control measure for acid rain? A Increasing the use of coal B Using catalytic converters in vehicles C Burning more fossil fuels D Adding more SO₂ to the atmosphere
20 Which acid is considered a strong acid? A Acetic acid B Citric acid C Hydrochloric acid D Carbonic acid
21 Acid rain damages buildings made of marble mainly because marble contains: A Calcium carbonate B Sodium chloride C Iron oxide D Silicon dioxide
22 A base that produces OH- ions in water is described by which concept? A Bronsted-Lowry concept B Lewis concept C Arrhenius concept D Proton-acceptor concept
23 According to the Lewis concept, an acid is: A A proton donor B A proton acceptor C An electron-pair acceptor D An electron-pair donor
24 Which reaction represents neutralization? A Acid + metal → salt + hydrogen B Acid + base → salt + water C Acid + carbonate → salt + water + CO₂ D Base + metal → salt + hydrogen
25 Which of the following is a limitation of the Arrhenius concept? A It explains the behaviour of acids and bases in water only. B It explains proton transfer in all solvents. C It explains electron pair donation. D It explains the amphoteric nature of water.