Chemistry MCQs
Chemistry MCQs cover organic, inorganic, physical, analytical, and biochemistry topics. Perfect for FSc, BSc, CSS, PMS, NTS, and competitive exams, they enhance concept mastery, analytical skills, speed, and accuracy for academic and job test success.
Q: Limewater turns milky in the presence of:
A) Hydrogen
B) Nitrogen
C) Oxygen
D) Carbon dioxide
✅ Correct Answer: D
Explanation: Limewater reacts with CO₂ to form calcium carbonate, which is milky.
Q: Acids taste:
A) Sour
B) Bitter
C) Salty
D) Sweet
✅ Correct Answer: A
Explanation: Sour taste is characteristic of acidic substances.
Q: Litmus paper turns red in the presence of:
A) Base
B) Salt
C) Neutral solution
D) Acid
✅ Correct Answer: D
Explanation: Acids cause blue litmus to turn red.
Q: Ammonia is a:
A) Strong base
B) Strong acid
C) Weak base
D) Weak acid
✅ Correct Answer: A
Explanation: Ammonia acts as a weak base, accepting protons in solution.
Q: Isotopes are atoms with the same atomic number but different:
A) Protons
B) Charges
C) Electrons
D) Mass numbers
✅ Correct Answer: D
Explanation: Isotopes differ in neutron number, affecting mass number.