Chemical bonding & molecular structure practice · Mixed difficulty

Option C ($o$-dichlorobenzene) is correct because the dipole moments of the C-Cl bonds add constructively due to their orientation, resulting in a non-zero net dipole moment.

Option C (Rusting of iron) is correct because rusting involves the formation of new chemical bonds between iron and oxygen.

Option B ($NH_4^+$) is correct because it has a tetrahedral geometry with bond angles of 109.5 degrees, which is larger than the bond angles in $NH_3$, $PCl_5$, and $SCl_2$. $PCl_5$ is incorrect because it has 120 and 90 degree angles, but the question asks for the maximum angle.

Option C (-0.75, 1.25) is correct because the formal charge on each oxygen is -0.75 and the P-O bond order is 1.25 in the phosphate ion.

Option C ($PF_5$ and $BrF_5$) is correct because they have different structures due to different numbers of lone pairs on the central atom.

Option D ($16.83$) is correct because it is the calculated percentage ionic character of HCl using the given bond length and dipole moment.

Option D ($BeCl_2$) is correct because Beryllium in $BeCl_2$ has an incomplete octet and can accept electron pairs, indicating residual bonding capacity.

Option B (A metallic solid) is correct because Cesium (Cs) is an alkali metal and exists as a metallic solid at room temperature.

Option C (Donation of electron pair) is correct because coordinate compounds are formed when one atom donates a pair of electrons to another atom to form a coordinate covalent bond.

Option C (Angular) is correct because SnCl2 has two bond pairs and one lone pair, resulting in a bent or angular shape due to the repulsion from the lone pair.

Option B (H and Br) is correct because the difference in electronegativity between H and Br is significant enough to create a polar covalent bond.

Option C (4U) is correct because lattice energy is proportional to the product of the charges of the ions. CaO has charges of +2 and -2, while NaCl has charges of +1 and -1. Therefore, the lattice energy of CaO is approximately 4 times that of NaCl.

Option C (NaCl) is correct because, among the given alkali metal chlorides, NaCl has the smallest cation (Na+) after Li+ and thus experiences stronger electrostatic attraction, leading to a higher melting point.

Option B (Lewis) is correct because Gilbert N. Lewis proposed the electronic theory of bonding, focusing on the role of valence electrons in forming chemical bonds.

Option B ($\mathrm{N} - \mathrm{N}$) is correct because nitrogen can form a triple bond (N≡N), which is stronger than the single bonds formed by C, O, and F.

Option B ($\mathrm{NH}_4^ +$) is correct because it has a tetrahedral geometry with bond angles of 109.5°, which is the largest among the given options.

Option A (Hydrogen bonds) is correct because the complementary base pairs in DNA (adenine-thymine and guanine-cytosine) are held together by hydrogen bonds.

Option B ($s{p^3}d$ hybridisation) is correct because tellurium in $TeCl_4$ has four bond pairs and one lone pair, resulting in a steric number of 5 and $sp^3d$ hybridization.

Option A ($NO_3^ - ,\,CO_3^{2 - }$) is correct because both ions have the same number of electrons (32) and a trigonal planar structure.

Option A is correct because adding electrons to form $\mathrm{C}_2^{2 - }$ increases bond order, thus decreasing bond length.

Option B (K and O2) is correct because potassium (K) is a highly electropositive metal and oxygen (O2) is a highly electronegative non-metal, leading to a large difference in electronegativity and thus ionic bond formation.

Option C (Chemical bonding) is correct because Linus Pauling received the Nobel Prize in Chemistry for his work on the nature of the chemical bond.

Option B (1) is correct because $\mathrm{L}{\mathrm{i}_2}$ has a bond order of 1, calculated from its electronic configuration.

Option B ($109^{\circ}$) is correct because carbon tetrachloride ($CCl_4$) has a tetrahedral geometry with bond angles of approximately 109.5 degrees.

Option B ($AgI$) is correct because silver halides are generally insoluble except for $AgF$, and among the insoluble ones, $AgI$ has the lowest solubility due to its high covalent character.

Option A (Chemical bond) is correct because a chemical bond is defined as the attractive force that holds atoms, ions, or other constituents together in chemical species.

Option A (${\mathrm{H}_2}$) is correct because it is a diatomic molecule formed by two identical atoms, resulting in equal sharing of electrons and no dipole moment.

Option A is correct because both the assertion and the reason are true, and the reason correctly explains why sodium sulfate is soluble while barium sulfate is not.

Option A ($C{H_4} < CHC{l_3} < C{H_2}C{l_2} < C{H_3}Cl$) is correct because the dipole moment increases as the symmetry decreases and the vector sum of bond dipoles increases, with $CH_4$ having zero dipole moment.

Option D ($s{p^3}d$ hybridized) is correct because phosphorus in $PCl_5$ has five bonding pairs and no lone pairs, resulting in $sp^3d$ hybridization and a trigonal bipyramidal geometry.