All Free Chemistry MCQs with Answers

• A. Poly-dentate ligand
• B. Chelate
• C. Mono dentate ligand
• D. hydrate

Explanation: Chelate ligands are a type of poly-dentate ligands that can form a ring structure with a metal ion by donating multiple lone pairs of…

• A. +7
• B. -7
• C. +6
• D. -6

Explanation: To determine the oxidation number of manganese (Mn) in the permanganate ion [MnO4]2-, we can assign oxidation numbers to the other…

• A. activation
• B. enameling
• C. corrosion
• D. coating

Explanation: It refers to the gradual degradation of metals through a chemical reaction with the surrounding environment.

• A. dry cell
• B. electrolytic cell
• C. galvanic cell
• D. both and and b

Explanation: Galvanic cells, also known as voltaic cells, generate electrical energy through spontaneous redox reactions.

• A. Sc
• B. Y
• C. Cd
• D. Co

Explanation: Galvanic cells, also known as voltaic cells, generate electrical energy through spontaneous redox reactions.

• A. I2O4 (iodine tetroxide)
• B. I4O2 (iodine dioxide)
• C. I2O5
• D. All are equally useful

Explanation: The correct answer is (c) I2O5 (iodine pentoxide).Why I2O5 is used for CO2 analysis:I2O5 is a powerful oxidizing agent and reacts readily…

• A. Fluorine is restricted to -1 oxidation state
• B. The correct answer is (b) fluorine follows octet rule and as well as extended octet rule.
• C. Fluorine has the lowest dissociation energy among the halogens
• D. both b& c

Explanation: Incorrect statement:Fluorine cannot break the octet rule: It lacks d-orbitals in its valence shell, so it cannot accommodate more than 8…

• A. F2
• B. Cl2
• C. Br2
• D. Iodine

Explanation: Van der Waals forces generally increase as the size of the molecule increases.

• A. F₂ (Fluorine gas)
• B. Cl₂ (Chlorine gas)
• C. Br₂ (Bromine gas)
• D. I₂ (Iodine)

Explanation: Fluorine's exceptional reactivity: Among the halogens, only fluorine gas (F₂) is powerful enough to react directly with gold under normal…

• A. Xe
• B. Kr
• C. Rn
• D. All of the above.

Explanation: Fluorine's exceptional reactivity:Fluorine is the most reactive element in the entire periodic table.

• A. XeF4
• B. XeOF4
• C. XeOF2
• D. NaXeO6.

Explanation: Sodium is +1 and each oxygen has -2. Xenon's oxidation state is +6 (1 x +1 + 6 x -2 = -12).Therefore, only NaXeO6 has xenon with an…

• A. Cl2
• B. I2 is a volatile solid
• C. Br2
• D. Cl2 is insoluble in water

Explanation: Iodine (I2) is a volatile solid. At room temperature, iodine sublimes directly from a solid to a purple-colored gas without passing…

• A. Small size
• B. High nuclear charge
• C. Both a and b
• D. No authorized justification yet

Explanation: Combining the effects of small size and high nuclear charge provides a more complete explanation.

• A. 1s22s22p3
• B. 1s22s22p63s23p1
• C. 1s22s22p4
• D. 1s22s22p63s23p64s23d1

Explanation: (d) 1s2 2s2 2p6 3s2 3p6 4s2 3d1: This configuration includes a partially filled 3d orbital, which is not a characteristic of Group IIA…

• A. 4
• B. 2
• C. 1
• D. 6

Explanation: In the network of silica (SiO2), each silicon atom is surrounded by (a) 4 oxygen atoms.Therefore, remembering the basic stoichiometry of…

• A. 26%
• B. 37%
• C. 27%
• D. < 2.6%

Explanation: Orthoboric acid's solubility in water varies with temperature. At 40°C, it's given as 2.6%.

• A. carbon is non-metal while silicon is semi-metal
• B. CO3 is an independent molecule while Si02 has network covalent structure
• C. CO2 forms multiple bond while silicon does not form multiple bonds
• D. Silicon has all sigma bonds.

Explanation: While all the listed options contain some truths about the differences between CO2 and SiO2, only one accurately explains their…

• A. Al2O3.2H20
• B. Na3AlF6
• C. A2O3.3H20
• D. Al2O3.H20

Explanation: Among the options you provided, the chief ore of aluminum is:(d) Al2O3.H2OThis is the chemical formula for hydrated alumina, also known as…

• A. Pb20
• B. Pb2O4
• C. PbO2
• D. All of the above

Explanation: Litharge (PbO) is the most common and stable oxide of lead in its lower oxidation state (+2).

• A. Beryllium
• B. Carbon
• C. Silicon
• D. Aluminium

Explanation: Aluminium: Aluminium commonly forms a tripositive ion (Al³⁺) by losing three electrons.Therefore, the correct answer to the question…