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Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
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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): The geometry of \( \text{BrF}_5 \) is square pyramidal. Reason (R): The central bromine atom in \( \text{BrF}_5 \) undergoes \( sp^3d^2 \) hybridisation with 5 bond pairs and 1 lone pair. 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 ozone (\( \text{O}_3 \)) molecule, the experimentally determined oxygen-oxygen bond length is:
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
Consider the following statements regarding chemical bonds and bond parameters: (A) Most ionic compounds consist of cations derived from metallic elements, but the ammonium ion (\( \text{NH}_4^+ \)) is an exception as it is made of non-metallic elements. (B) Noble gas compounds such as \( \text{XeF}_2 \) and \( \text{KrF}_2 \) demonstrate that the octet rule is not universally valid. (C) The covalent radius of chlorine is equal to \( 198\text{ pm} \). (D) The van der Waals radius represents the overall size of the atom which includes its valence shell in a nonbonded situation. Choose the correct answer from the options given below:
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
According to the VSEPR theory, the correct decreasing order of repulsive interactions between electron pairs is:
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
Given the ionization enthalpy of \( \text{Na(g)} \) is \( +495.8\text{ kJ mol}^{-1} \) and the electron gain enthalpy of \( \text{Cl(g)} \) is \( -348.7\text{ kJ mol}^{-1} \), calculate the net enthalpy change for the gaseous ion formation: \( \text{Na(g)} + \text{Cl(g)} \to \text{Na}^+(\text{g}) + \text{Cl}^-(\text{g}) \).
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
Consider the following statements regarding the repulsive interactions in VSEPR theory: (A) \( \text{Lone pair (lp)} - \text{Lone pair (lp)} > \text{Lone pair (lp)} - \text{Bond pair (bp)} > \text{Bond pair (bp)} - \text{Bond pair (bp)} \) (B) The presence of lone pairs on the central atom causes deviations from ideal bond angles. (C) In \( \text{H}_2\text{O} \), there are two lone pairs and two bond pairs on the central oxygen atom. (D) In ammonia, the \( \text{H}-\text{N}-\text{H} \) bond angle is \( 109.5^\circ \). Choose the correct answer from the options given below:
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
Water (\( \text{H}_2\text{O} \)) has a net dipole moment of \( 1.85\text{ D} \) and a bond angle of \( 104.5^\circ \). Treating each \( \text{O}-\text{H} \) bond dipole as \( \mu_{\text{bond}} \), and using \( \mu_{\text{net}} = 2\mu_{\text{bond}}\cos(\theta/2) \) where \( \cos(52.25^\circ) \approx 0.612 \), the individual \( \text{O}-\text{H} \) bond dipole moment is:
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
If the energy required to dissociate one mole of \( \text{H}_2 \) gas into atoms is \( 435.8\text{ kJ mol}^{-1} \), calculate the bond dissociation energy per single \( \text{H}-\text{H} \) bond in Joules. (Take \( N_A = 6.022 \times 10^{23}\text{ mol}^{-1} \))
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
For chlorine, the van der Waals radius is \( 180\text{ pm} \) and the covalent radius is \( 99\text{ pm} \). Calculate the difference between the non-bonded internuclear distance between two chlorine atoms of adjacent molecules in solid chlorine and the bonded internuclear distance in a \( \text{Cl}_2 \) molecule.
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
A molecule has a dipole moment of \( 1.50\text{ D} \). Expressed in SI units (\( \text{C m} \)), this value is closest to: (Given: \( 1\text{ D} = 3.33564 \times 10^{-30}\text{ C m} \))
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
In a molecule of \( \text{BrF}_5 \), calculate the difference between the total number of bond pairs and the total number of lone pairs on the central bromine atom.
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
According to the tabulated covalent radii, the covalent radius of carbon is \( 77\text{ pm} \) (single bond) and that of chlorine is \( 99\text{ pm} \). If the bond length in \( \text{C}-\text{Cl} \) is taken as the sum of their covalent radii, calculate the percentage increase in bond length when comparing a \( \text{C}-\text{C} \) single bond (\( 154\text{ pm} \)) to this estimated \( \text{C}-\text{Cl} \) bond.
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): A sigma (\( \sigma \)) bond is stronger than a pi (\( \pi \)) bond. Reason (R): The extent of overlapping of atomic orbitals along the internuclear axis in a sigma bond is greater than the sidewise overlapping in a pi bond. In the light of the above statements, choose the correct answer from the options given below:
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
Consider the following statements regarding the octet rule and its limitations: (A) \( \text{NO} \) and \( \text{NO}_2 \) are odd-electron molecules where the octet rule is not satisfied for all atoms. (B) In \( \text{SCl}_2 \), sulfur disobeys the octet rule by forming an expanded octet. (C) Noble gases like xenon and krypton do not form any chemical compounds under any conditions. (D) The octet theory does not account for the shapes of molecules. How many of the above statements are correct?
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
How many total valence electrons are involved in bonding (bonding pairs \( \times 2 \)) and non-bonding states on the central chlorine atom in a molecule of chlorine trifluoride (\( \text{ClF}_3 \))?
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
In \( \text{SF}_4 \), the lone pair of electrons on the central sulfur atom preferentially occupies:
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
Match List-I with List-II: List-I (Molecule / Species) List-II (Arrangement / Geometry) A \( \text{HgCl}_2 \) I Trigonal bipyramidal B \( \text{NH}_4^+ \) II Octahedral C \( \text{PCl}_5 \) III Linear D \( \text{SF}_6 \) IV Tetrahedral Choose the correct answer from the options given below:
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): The bond dissociation enthalpy of \( \text{N}_2 \) is higher than that of \( \text{O}_2 \). Reason (R): Nitrogen has a bond order of 3 whereas oxygen has a bond order of 2, and bond enthalpy increases with increase in bond order. 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 an \( \text{AB}_4\text{E} \) molecule such as \( \text{SF}_4 \), the lone pair occupies an equatorial position rather than an axial position. If placed in an axial position, how many lone pair–bond pair (\( \text{lp}-\text{bp} \)) repulsions at approximately \( 90^\circ \) would it experience?
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
In \( \text{H}_2\text{SO}_4 \), the sulfur atom is surrounded by how many valence electrons in the expanded octet structure containing two \( \text{S}=\text{O} \) double bonds and two \( \text{S}-\text{OH} \) single bonds?
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
Calculate the sum of the total number of valence electrons surrounding the central atoms in \( \text{BeH}_2 \) and \( \text{SF}_6 \) according to their Lewis representations.
Read answer →Chemistry · CHEMICAL BONDING AND MOLECULAR STRUCTURE
Given below are two statements: Statement I: The actual shape of \( \text{SO}_2 \) molecule is bent or V-shaped with a bond angle of \( 119.5^\circ \). Statement II: The lone pair-bond pair repulsion in \( \text{SO}_2 \) reduces the bond angle from the expected \( 120^\circ \). 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
