Chemistry MCQs
Our Chemistry MCQs section is tailored for students and job seekers aiming for excellence in academic and competitive exams. It includes a vast selection of multiple-choice questions covering organic chemistry, inorganic chemistry, analytical chemistry, physical chemistry, and biochemistry. These MCQs are suitable for FSc, BSc, pre-medical, and pre-engineering students, as well as CSS, PMS, NTS, and other competitive exams in Pakistan. Designed by subject experts, the questions help reinforce key concepts, test analytical skills, and improve speed and accuracy. Each topic includes beginner to advanced-level questions with a focus on the latest syllabus and past papers. If you are preparing for university entry tests or government job recruitment exams, this resource offers an excellent opportunity to master chemistry topics effectively.
Q: The main ore of aluminum is?
A) Magnetite
B) Galena
C) Bauxite
D) Hematite
✅ Correct Answer: C
Explanation: Bauxite is the primary source of aluminum.
Q: Which element forms the basis of life?
A) Carbon
B) Hydrogen
C) Nitrogen
D) Oxygen
✅ Correct Answer: A
Explanation: Carbon forms the backbone of all organic molecules.
Q: The number of valence electrons in oxygen is?
A) 6
B) 2
C) 4
D) 8
✅ Correct Answer: A
Explanation: Oxygen has 6 electrons in its outer shell.
Q: An example of a polyatomic ion is?
A) Na⁺
B) OH⁻
C) Cl⁻
D) K⁺
✅ Correct Answer: B
Explanation: Hydroxide (OH⁻) is a common polyatomic ion.
Q: Which compound has a triple bond?
A) Ethene
B) Ethyne
C) Propane
D) Ethane
✅ Correct Answer: B
Explanation: Ethyne (C₂H₂) has a triple carbon-carbon bond.
Q: Which of the following is a diatomic molecule?
A) Carbon
B) Sodium
C) Nitrogen
D) Neon
✅ Correct Answer: C
Explanation: N₂ is a diatomic molecule naturally found in air.
Q: The law of conservation of mass was proposed by?
A) Newton
B) Mendeleev
C) Lavoisier
D) Dalton
✅ Correct Answer: C
Explanation: Lavoisier stated that mass is neither created nor destroyed in chemical reactions.
Q: Which gas turns limewater milky?
A) Oxygen
B) Carbon dioxide
C) Nitrogen
D) Hydrogen
✅ Correct Answer: B
Explanation: CO₂ reacts with limewater to form insoluble CaCO₃.
Q: Which type of reaction is burning of wood?
A) Decomposition
B) Combustion
C) Substitution
D) Combination
✅ Correct Answer: B
Explanation: Combustion involves reaction with oxygen producing heat.