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Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
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Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
Match List-I with List-II: List-I (Molecule / Ion) List-II (Geometry / Shape) A \( \text{SF}_4 \) I Square planar B \( \text{BrF}_5 \) II See-saw C \( \text{ClF}_3 \) III Square pyramidal D \( \text{XeF}_4 \) IV T-shaped Choose the correct answer from the options given below:
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
Which of the following molecules has a square planar shape with two lone pairs of electrons on the central atom?
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
Consider the following molecules/ions having no lone pairs on the central atom: (A) \( \text{HgCl}_2 \) — Linear geometry with bond angle \( 180^\circ \) (B) \( \text{BF}_3 \) — Trigonal planar geometry with bond angle \( 120^\circ \) (C) \( \text{NH}_4^+ \) — Tetrahedral geometry with bond angle \( 109.5^\circ \) (D) \( \text{SF}_6 \) — Octahedral geometry with bond angle \( 90^\circ \) Which of the above pairs/descriptions are correct according to VSEPR theory?
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
A pi (\( \pi \)) bond is formed by which type of orbital overlapping?
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
Given the net enthalpy for \( \text{Na}^+(\text{g}) + \text{Cl}^-(\text{g}) \) formation from atoms is \( +147.1\text{ kJ mol}^{-1} \) and the enthalpy of lattice formation of \( \text{NaCl(s)} \) is \( -788.0\text{ kJ mol}^{-1} \), what is the total enthalpy change (\( \Delta H_{\text{rxn}} \)) for \( \text{Na(g)} + \text{Cl(g)} \to \text{NaCl(s)} \)?
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
The bond dissociation enthalpies for breaking the two successive \( \text{O}-\text{H} \) bonds in gaseous water are \( 502\text{ kJ mol}^{-1} \) and \( 427\text{ kJ mol}^{-1} \), respectively. Calculate the total energy required to completely atomize \( 3.6\text{ g} \) of gaseous \( \text{H}_2\text{O} \) into gaseous \( \text{H} \) and \( \text{O} \) atoms.
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
According to Fajans' rules, which of the following combinations favors the highest covalent character in an ionic bond?
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
Which of the following statements strictly describes the definition of the lattice enthalpy of an ionic compound?
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): In the formation of calcium fluoride (\( \text{CaF}_2 \)), calcium is assigned a positive electrovalence of two. Reason (R): In a water molecule, hydrogen atoms attain a duplet of electrons while the oxygen atom attains an octet of electrons. In the light of the above statements, choose the correct answer from the options given below:
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
In the shown Lewis electron dot diagram of covalent bonding, how many total lone pairs of electrons are present on the chlorine atoms in a single \( \text{CCl}_4 \) molecule?
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
The mathematical expression for calculating the formal charge (\( \text{F.C.} \)) of an atom in a Lewis structure is given by:
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
The dipole moment of \( \text{HCl} \) is \( 1.07\text{ D} \) and its bond length is \( 127\text{ pm} \). Given that \( 1\text{ D} = 3.33564 \times 10^{-30}\text{ C m} \) and electronic charge \( e = 1.602 \times 10^{-19}\text{ C} \), the fractional electronic charge (\( \delta = q/e \)) residing on each atom is approximately:
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
Calculate the total number of \( \sigma \) bonds, \( \pi \) bonds, and lone pairs of electrons respectively on the central atom in an \( \text{I}_3^- \) ion (which is isoelectronic with \( \text{XeF}_2 \), having an \( \text{AB}_2\text{E}_3 \) steric arrangement).
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
Refer to the shapes of molecules with no lone pairs shown in Fig. 4.6 (\( \text{BeCl}_2 \), \( \text{BF}_3 \), \( \text{CH}_4 \), and \( \text{PCl}_5 \)). In \( \text{PCl}_5 \), two different bond angles (\( 90^\circ \) and \( 120^\circ \)) are depicted. Why do axial and equatorial bonds in this molecule experience different extents of repulsion according to VSEPR theory?
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
Consider the following molecules/ions: (A) \( \text{BF}_3 \) (B) \( \text{SF}_6 \) (C) \( \text{NO}_2 \) (D) \( \text{AlCl}_3 \) How many of the above species exhibit an incomplete octet (less than 8 electrons) around the central atom? Which of the above statements is/are correct?
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
Given below are two statements: Statement I: With increase in bond order, bond enthalpy decreases and bond length increases. Statement II: Isoelectronic molecules and ions such as \( \text{F}_2 \) and \( \text{O}_2^{2-} \) have identical bond orders. In the light of the above statements, choose the most appropriate answer from the options given below:
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
The dipole moment of chloroform (\( \text{CHCl}_3 \)) is \( 1.04\text{ D} \). How many molecules of \( \text{CHCl}_3 \) must align end-to-end so that their sum of dipole moments equals \( 1.00\text{ C m} \)? (\( 1\text{ D} = 3.33564 \times 10^{-30}\text{ C m} \))
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
Given below are two statements: Statement I: Valence bond theory was originally introduced by Heitler and London in 1927 and later developed by Pauling and others. Statement II: Valence bond theory explains that bond formation is always an endothermic process requiring energy input from surroundings. In the light of the above statements, choose the most appropriate answer from the options given below:
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
Given the bond dissociation enthalpy of \( \text{N}_2(\text{g}) \) is \( 946.0\text{ kJ mol}^{-1} \) and that of \( \text{O}_2(\text{g}) \) is \( 498.0\text{ kJ mol}^{-1} \). If a gaseous mixture contains \( 0.5\text{ mol} \) of \( \text{N}_2 \) and \( 1.5\text{ mol} \) of \( \text{O}_2 \), what is the total energy required to completely dissociate all molecules into isolated gaseous atoms?
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
Given the ionization enthalpy of \( \text{Na(g)} \) is \( +495.8\text{ kJ mol}^{-1} \), the electron gain enthalpy of \( \text{Cl(g)} \) is \( -348.7\text{ kJ mol}^{-1} \), and the lattice enthalpy of \( \text{NaCl(s)} \) is \( +788\text{ kJ mol}^{-1} \). What is the net enthalpy change for the formation of \( 1\text{ mole} \) of solid \( \text{NaCl} \) from \( \text{Na(g)} \) and \( \text{Cl(g)} \)?
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
Langmuir refined Lewis's cubical model of the atom by abandoning which of the following ideas?
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
Consider the following statements regarding the molecular geometries based on VSEPR theory: (A) The shape of \( \text{SO}_2 \) is bent with an \( \text{O}-\text{S}-\text{O} \) angle reduced to approximately \( 119.5^\circ \). (B) In \( \text{SF}_4 \), the lone pair occupies an equatorial position to minimize lp–bp repulsions. (C) In \( \text{ClF}_3 \), the molecule adopts a trigonal planar shape. (D) In \( \text{XeF}_4 \), the two lone pairs are oriented trans to each other, resulting in a square planar geometry. Choose the correct answer from the options given below:
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
