🧪 Chemistry MCQs with Answers
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Prepare Chemistry MCQs with detailed answers covering basic concepts, chemical reactions, atomic structure, and important topics. Ideal for scholarship tests, job interview tests, and competitive exams.
1. The atomic number of Oxygen is:
A) 6
B) 8
C) 10
D) 12
Answer: B) 8
2. Who is known as the father of modern chemistry?
A) Dalton
B) Lavoisier
C) Mendeleev
D) Rutherford
Answer: B) Lavoisier
3. H₂O is the chemical formula of:
A) Oxygen
B) Water
C) Hydrogen Peroxide
D) Hydroxide
Answer: B) Water
4. The nucleus of an atom contains:
A) Electrons only
B) Protons and Neutrons
C) Protons only
D) Neutrons only
Answer: B) Protons and Neutrons
5. The pH of pure water is:
A) 5
B) 7
C) 9
D) 10
Answer: B) 7
6. Which gas is used in the preparation of soda water?
A) Oxygen
B) Carbon dioxide
C) Hydrogen
D) Nitrogen
Answer: B) Carbon dioxide
7. NaCl is commonly known as:
A) Baking soda
B) Common salt
C) Washing soda
D) Bleaching powder
Answer: B) Common salt
8. The chemical symbol of Gold is:
A) Ag
B) Au
C) Gd
D) Go
Answer: B) Au
9. The process of solid changing directly into gas is called:
A) Condensation
B) Sublimation
C) Evaporation
D) Fusion
Answer: B) Sublimation
10. Which acid is present in lemon?
- A) Lactic acid
B) Citric acid
C) Acetic acid
D) Oxalic acid
Answer: B) Citric acid
11. The lightest gas is:
A) Helium
B) Hydrogen
C) Nitrogen
D) Oxygen
Answer: B) Hydrogen
12. Which particle has no charge?
A) Proton
B) Electron
C) Neutron
D) Positron
Answer: C) Neutron
13. Which is the most abundant element in the human body?
A) Oxygen
B) Carbon
C) Hydrogen
D) Nitrogen
Answer: A) Oxygen
14. Chemical symbol of Sodium is:
B) Sd
C) Na
D) S
Answer: C) Na
15. The study of carbon compounds is called:
A) Inorganic Chemistry
B) Organic Chemistry
C) Biochemistry
D) Physical Chemistry
Answer: B) Organic Chemistry
16. The chemical formula of Ammonia is:
A) HCl
B) NH₃
C) CH₄
D) H₂SO₄
Answer: B) NH₃
17. Rusting of iron is an example of:
A) Physical change
B) Chemical change
C) Temporary change
D) None
Answer: B) Chemical change
18. The atomic number of Carbon is:
A) 4
B) 6
C) 8
D) 12
Answer: B) 6
19. The gas used in balloons is:
A) Helium
B) Oxygen
C) Hydrogen
D) Nitrogen
Answer: A) Helium
20. Which acid is known as "King of Chemicals"?
A) HCl
B) H₂SO₄
C) HNO₃
D) H₃PO₄
Answer: B) H₂SO₄ (Sulfuric Acid)
21. The smallest particle of an element is:
A) Atom
B) Molecule
C) Proton
D) Electron
Answer: A) Atom
22. Which gas turns lime water milky?
A) Oxygen
B) Carbon dioxide
C) Ammonia
D) Nitrogen
Answer: B) Carbon dioxide
23. The process of separating liquids by boiling and condensation is:
A) Filtration
B) Sublimation
C) Distillation
D) Evaporation
Answer: C) Distillation
24. Which is a noble gas?
A) Oxygen
B) Helium
C) Hydrogen
D) Carbon
Answer: B) Helium
25. CaCO₃ is the chemical formula of:
A) Baking soda
B) Washing soda
C) Marble / Limestone
D) Gypsum
Answer: C) Marble / Limestone
26. Chemical symbol of Iron is:
A) In
B) Ir
C) Fe
D) Io
Answer: C) Fe
27. The charge on an electron is:
A) Positive
B) Negative
C) Neutral
D) None
Answer: B) Negative
28. Which metal is liquid at room temperature?
A) Sodium
B) Mercury
C) Iron
D) Potassium
Answer: B) Mercury
29. The study of matter and its changes is called:
A) Biology
B) Chemistry
C) Physics
D) Geology
Answer: B) Chemistry
30. The molecular formula of Methane is:
A) CH₄
B) C₂H₆
C) C₃H₈
D) C₄H₁₀
Answer: A) CH₄
31. Which element is essential for respiration?
A) Nitrogen
B) Oxygen
C) Hydrogen
D) Carbon
Answer: B) Oxygen
32. What is the pH of an acidic solution?
A) Less than 7
B) Equal to 7
C) Greater than 7
D) None
Answer: A) Less than 7
33. Which gas is known as laughing gas?
A) CO₂
B) N₂O
C) NH₃
D) H₂S
Answer: B) N₂O
34. The process of loss of electrons is called:
A) Oxidation
B) Reduction
C) Neutralization
D) Ionization
Answer: A) Oxidation
35. The chemical name of table sugar is:
A) Glucose
B) Fructose
C) Sucrose
D) Maltose
Answer: C) Sucrose
36. Which gas is used in fire extinguishers?
A) Oxygen
B) Carbon dioxide
C) Helium
D) Methane
Answer: B) Carbon dioxide
37. Which particle revolves around the nucleus?
A) Proton
B) Neutron
C) Electron
D) Ion
Answer: C) Electron
38. Which of the following is not a halogen?
A) Fluorine
B) Chlorine
C) Bromine
D) Oxygen
Answer: D) Oxygen
39. Chemical formula of Hydrochloric acid is:
A) HCl
B) H₂SO₄
C) HNO₃
D) H₂CO₃
Answer: A) HCl
40. Which law states that "Mass can neither be created nor destroyed"?
A) Law of Multiple Proportions
B) Law of Constant Proportions
C) Law of Conservation of Mass
D) Boyle’s Law
Answer: C) Law of Conservation of Mass
41. Which element is liquid at room temperature other than Mercury?
A) Bromine
B) Sodium
C) Calcium
D) Potassium
Answer: A) Bromine
42. Which is the lightest metal?
A) Sodium
B) Lithium
C) Aluminum
D) Magnesium
Answer: B) Lithium
43. The symbol 'K' stands for which element?
A) Krypton
B) Potassium
C) Calcium
D) Cadmium
Answer: B) Potassium
44. What is the atomic number of Hydrogen?
A) 0
B) 1
C) 2
D) 3
Answer: B) 1
45. Which gas supports burning?
A) Oxygen
B) Hydrogen
C) Nitrogen
D) Carbon dioxide
Answer: A) Oxygen
46. Which acid is used in car batteries?
A) Nitric acid
B) Sulfuric acid
C) Hydrochloric acid
D) Acetic acid
Answer: B) Sulfuric acid
47. Ozone is:
A) O₂
B) O₃
C) O₄
D) O⁻
Answer: B) O₃
48. The atomic mass of Carbon is:
A) 6
B) 12
C) 14
D) 16
Answer: B) 12
49. Which of these is not a noble gas?
A) Helium
B) Neon
C) Argon
D) Hydrogen
Answer: D) Hydrogen
50. Which branch of chemistry deals with the study of compounds containing metals?
A) Organic Chemistry
B) Inorganic Chemistry
C) Biochemistry
D) Physical Chemistry
Answer: B) Inorganic Chemistry
