All Free Chemistry MCQs with Answers

• A. 17
• B. 3
• C. 1
• D. 8

Explanation: Chlorine atom has 7 electrons in it's valence shell, however the question is asking about chloride ion which has 1 extra electron.

• A. Cl2
• B. CH4
• C. HF
• D. HI

Explanation: Each sp3 hybrid orbital of carbon overlaps 1s-orbital of hydrogen to form C-H sigma bonds.

• A. Greater
• B. Zero
• C. Lesser
• D. Variable

Explanation: Down the group ionization energy decreases due to increase in number of shell, shielding effect and atomic size.

• A. Increases from left to right in a period
• B. Increases from top to bottom in a group.
• C. Does not change in a period
• D. Does not change in a group

Explanation: Ionization energy is increases from left to right in a period.

• A. Pairing of electrons
• B. Shifts of atoms
• C. Sharing of atoms
• D. None of the above

Explanation: The HF bond is formed by the sharing of the electrons, resulting in a strong bond that is highly polar.

• A. KO2, NO2
• B. K2O2, KO3
• C. K2O,NO2
• D. NO2, N2O2

Explanation: In KO2, O2- → (superoxide) has one unpaired electron and NO2 also has one unpaired electron. Thus,KO2 and NO2 are paramagnetic.

• A. Atomic/ionic radii
• B. Shielding effect
• C. Nature of orbital
• D. All of the above

Explanation: 1.atomicsize 2.shielding effect 3.effective nuclear charge.

• A. High I. E of metal
• B. Low lattice energy
• C. Low E.A of non-metal
• D. Low I.E of metal

Explanation: Metals of group IA and IIA have low ionization energy means high electropositive character and great tendency to form ionic bond.

• A. HI
• B. HF
• C. HCI
• D. HBr

Explanation: %ionic character is directly related to electronegativity difference.

• A. The smaller size of Li+ imparts significant covalent character in LiF
• B. The hydration energies of Li+ and F- are quite high
• C. The lattice energy of LiF is quite high due to the smaller size of Li+ and F-
• D. LiF has a strong polymeric network in solid form

Explanation: Due to the very small ionic radii of both Li⁺ and F⁻, the electrostatic attraction between them is extremely strong.

• A. II > III > I > IV
• B. II > III = I > IV
• C. III > IV > I > II
• D. IV > I > III > II

Explanation: Bond length is determined by bond order. The order from longest to shortest is single bond (II, III), partial double bond due to resonance…

• A. Nitrogen lacks available d-orbitals for bonding
• B. The absence of NCl₅ is due to its instability
• C. Nitrogen's smaller atomic size prevents NCl₅ formation
• D. Nitrogen's inertness prevents NCl₅ formation

Explanation: Nitrogen is in the second period and has only s and p orbitals in its valence shell, limiting it to a maximum of four bonds.

• A. BeF₂
• B. BCl₃
• C. NH₃
• D. ClF₃

Explanation: According to VSEPR theory, chlorine trifluoride (ClF₃) has a central chlorine atom with three bonding pairs and two lone pairs of…

• A. The number of unpaired p-electrons
• B. The number of paired d-electrons
• C. The number of unpaired s-and p-electrons
• D. The total number of s-and p-electrons in the outermost shell

Explanation: For elements in the second period, the maximum covalency is determined by the total number of valence orbitals available, which is one…

• A. To decrease the number of electrons in the outermost shell
• B. To attain an inert gas configuration
• C. To increase the number of electrons in the outermost shell
• D. To attain 18 electrons in the outermost shell

Explanation: Atoms form chemical bonds to achieve a more stable electron configuration, which is typically the configuration of the noble gases (like…

• A. Ionization energy of A is high but electron affinity of B is low
• B. The ionization energy of A is low but the electron affinity of B is high
• C. Both ionization energy of A and electron affinity of B are high
• D. Both ionization energy of A and electron affinity of B are low

Explanation: Ionic bond formation involves the transfer of electrons. This is most favorable when one atom (the metal) can lose an electron easily (low…

• A. NaCl
• B. CsF
• C. KCl
• D. HF

Explanation: Ionic character is greatest when the difference in electronegativity between the two atoms is largest.

• A. Angular
• B. Trigonal pyramidal
• C. Tetrahedral
• D. See-saw

Explanation: An AB₄ molecule has a central atom bonded to four surrounding atoms. Such species can adopt geometries like tetrahedral (AX₄), see-saw…

• A. Br-Br > I-I
• B. Cl-Cl < F-F
• C. C≡ C < N≡ N
• D. All are correct

Explanation: This statement is incorrect. While bond energy generally increases up a group, the F-F bond is anomalously weak due to strong repulsion…

• A. I only
• B. I and II only
• C. I and III only
• D. II only
• E. I, II and III

Explanation: Bond energy is a critical concept in understanding chemical bonding and is defined through multiple perspectives:Option I: It is indeed…