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: 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.
Q: An example of a diatomic molecule is:
A) CO₂
B) CH₄
C) H₂O
D) H₂
✅ Correct Answer: D
Explanation: Diatomic molecules like H₂ consist of two atoms of the same element.
Q: The bond formed by sharing electrons is known as:
A) Metallic
B) Covalent
C) Ionic
D) Van der Waals
✅ Correct Answer: B
Explanation: Covalent bonds involve sharing of electrons between atoms.
Q: NaOH is commonly known as:
A) Vinegar
B) Caustic soda
C) Bleach
D) Baking soda
✅ Correct Answer: B
Explanation: Sodium hydroxide is also called caustic soda, a strong base.
Q: Elements in the same group have similar:
A) Chemical properties
B) Mass
C) Charges
D) Densities
✅ Correct Answer: A
Explanation: Similar outer electron configurations give similar reactivity.
Q: When iron reacts with oxygen and water, it forms:
A) Rust
B) Copper oxide
C) Iron carbonate
D) Iron sulfate
✅ Correct Answer: A
Explanation: Rust is hydrated iron(III) oxide formed by oxidation.