Molecule Identification and Lone Pair Calculation
The question asks to identify the molecule (X) with the lowest dipole moment among the given options and determine the number of lone pairs on its central atom.
Molecular Analysis
Let's analyze the structure, polarity, and lone pairs for each molecule:
- $\text{H}_2\text{S}$: Central atom Sulfur (S) has 2 bonding pairs and 2 lone pairs. Geometry is bent, and it's a polar molecule.
- $\text{H}_2\text{O}$: Central atom Oxygen (O) has 2 bonding pairs and 2 lone pairs. Geometry is bent, and it's a highly polar molecule.
- $\text{NF}_3$: Central atom Nitrogen (N) has 3 bonding pairs and 1 lone pair. Geometry is trigonal pyramidal, and it's a polar molecule.
- $\text{NH}_3$: Central atom Nitrogen (N) has 3 bonding pairs and 1 lone pair. Geometry is trigonal pyramidal, and it's a polar molecule.
- $\text{CHCl}_3$: Central atom Carbon (C) has 4 bonding pairs (1 C-H, 3 C-Cl) and 0 lone pairs. The molecule has a tetrahedral geometry. Although C-Cl bonds are polar, the symmetrical arrangement causes the bond dipoles to largely cancel out, resulting in a very low dipole moment, often considered effectively nonpolar in comparisons.
Lowest Dipole Moment Determination
Comparing the molecules:
- $\text{H}_2\text{O}$ and $\text{NH}_3$ are significantly polar.
- $\text{H}_2\text{S}$ is polar, but less so than water.
- $\text{NF}_3$ is polar, with a dipole moment around 0.23 D.
- $\text{CHCl}_3$, due to its symmetrical tetrahedral structure, has bond dipoles that nearly cancel, leading to the lowest dipole moment among the choices (also around 0.23 D, but often considered the least polar due to the cancellation effect).
Therefore, $\text{CHCl}_3$ is the molecule (X) with the lowest dipole moment.
Lone Pair Count
The central atom in $\text{CHCl}_3$ is Carbon (C). Carbon has 4 valence electrons and forms 4 single bonds with Hydrogen and Chlorine atoms. All valence electrons are used in bonding.
Number of lone pairs on the central atom (C) = $\frac{\text{Valence electrons} - \text{Bonding electrons}}{2} = \frac{4 - (4 \times 2)}{2} = \frac{4-8}{2}$ (Incorrect formula application, should consider valence electrons minus bonds = lone pairs). Correct calculation: Total valence electrons = 4. Electrons used in 4 bonds = 4. Lone pair electrons = 4 - 4 = 0. Thus, 0 lone pairs.
The number of lone pairs of electrons present on the central atom of molecule (X) is 0.
Similar Questions
- A 'p'-block element (E) and hydrogen form a binary cation $(\text{EH}_x)^+$, while $\text{EH}_3$ on treatment with $\text{K}_2\text{HgI}_4$ in alkaline medium gives a precipitate of basic mercury(II)amido-iodine. Given below are first ionisation enthalpy values ($\text{kJ mol}^{-1}$) for first element each from group 13, 14, 15 and 16. Identify the correct first ionisation enthalpy value for element E.
- $[\text{Ni}(\text{PPh}_3)_2\text{Cl}_2]$ is a paramagnetic complex. Identify the INCORRECT statements about this complex.
A. The complex exhibits geometrical isomerism.
B. The complex is white in colour.
C. The calculated spin-only magnetic moment of the complex is 2.84 BM.
D. The calculated CFSE (Crystal Field Stabilization Energy) of Ni in this complex is $-0.8 \, \Delta_0$.
E. The geometrical arrangement of ligands in this complex is similar to that in $\text{Ni(CO)}_4$.
Choose the correct answer from the options given below : - Given below are two statements :
Statement I : The first ionization enthalpy of Cr is lower than that of Mn.
Statement II : The second and third ionization enthalpies of Cr are higher than those of Mn.
In the light of the above statements, choose the correct answer from the options given below : - Given below are two statements :
Statement I : Elements 'X' and 'Y' are the most and least electronegative elements, respectively among N, As, Sb and P. The nature of the oxides $\text{X}_2\text{O}_3$ and $\text{Y}_2\text{O}_3$ is acidic and amphoteric, respectively.
Statement II : $\text{BCl}_3$ is covalent in nature and gets hydrolysed in water. It produces $[\text{B(OH)}_4]^-$ and $[\text{B(H}_2\text{O)}_6]^{3+}$ in aqueous medium.
In the light of the above statements, choose the correct answer from the options given below : Given below are two statements :
Statement I : $\text{C} < \text{O} < \text{N} < \text{F}$ is the correct order in terms of first ionization enthalpy values.
Statement II : $\text{S} > \text{Se} > \text{Te} > \text{Po} > \text{O}$ is the correct order in terms of the magnitude of electron gain enthalpy values.
In the light of the above statements, choose the correct answer from the options given below :- If the enthalpy of sublimation of Li is $155 \text{ kJ mol}^{-1}$, enthalpy of dissociation of $\text{F}_2$ is $150 \text{ kJ mol}^{-1}$, ionization enthalpy of Li is $520 \text{ kJ mol}^{-1}$, electron gain enthalpy of F is $-313 \text{ kJ mol}^{-1}$, standard enthalpy of formation of LiF is $-594 \text{ kJ mol}^{-1}$. The magnitude of lattice enthalpy of LiF is _________ $\text{kJ mol}^{-1}$. (Nearest Integer)
- Among the following oxides of 3d elements, the number of mixed oxides are _________.
$\text{Ti}_2\text{O}_3, \text{V}_2\text{O}_4, \text{Cr}_2\text{O}_3, \text{Mn}_3\text{O}_4, \text{Fe}_3\text{O}_4, \text{Fe}_2\text{O}_3, \text{Co}_3\text{O}_4$ - Consider three metal chlorides x, y and z, where x is water soluble at room temperature, y is sparingly soluble in water at room temperature and z is soluble in hot water. x, y and z are respectively
- In the Group analysis of cations, $\text{Ba}^{2+}$ & $\text{Ca}^{2+}$ are precipitated respectively as
- "X" is an oxoanion of the lightest element of group 7 (in the periodic table). The metal is in +6 oxidation state in "X". The color of the potassium salt of X is
Important Questions from Inorganic Chemistry
- A 'p'-block element (E) and hydrogen form a binary cation $(\text{EH}_x)^+$, while $\text{EH}_3$ on treatment with $\text{K}_2\text{HgI}_4$ in alkaline medium gives a precipitate of basic mercury(II)amido-iodine. Given below are first ionisation enthalpy values ($\text{kJ mol}^{-1}$) for first element each from group 13, 14, 15 and 16. Identify the correct first ionisation enthalpy value for element E.
- $[\text{Ni}(\text{PPh}_3)_2\text{Cl}_2]$ is a paramagnetic complex. Identify the INCORRECT statements about this complex.
A. The complex exhibits geometrical isomerism.
B. The complex is white in colour.
C. The calculated spin-only magnetic moment of the complex is 2.84 BM.
D. The calculated CFSE (Crystal Field Stabilization Energy) of Ni in this complex is $-0.8 \, \Delta_0$.
E. The geometrical arrangement of ligands in this complex is similar to that in $\text{Ni(CO)}_4$.
Choose the correct answer from the options given below : - Given below are two statements :
Statement I : The first ionization enthalpy of Cr is lower than that of Mn.
Statement II : The second and third ionization enthalpies of Cr are higher than those of Mn.
In the light of the above statements, choose the correct answer from the options given below : - Given below are two statements :
Statement I : Elements 'X' and 'Y' are the most and least electronegative elements, respectively among N, As, Sb and P. The nature of the oxides $\text{X}_2\text{O}_3$ and $\text{Y}_2\text{O}_3$ is acidic and amphoteric, respectively.
Statement II : $\text{BCl}_3$ is covalent in nature and gets hydrolysed in water. It produces $[\text{B(OH)}_4]^-$ and $[\text{B(H}_2\text{O)}_6]^{3+}$ in aqueous medium.
In the light of the above statements, choose the correct answer from the options given below : Given below are two statements :
Statement I : $\text{C} < \text{O} < \text{N} < \text{F}$ is the correct order in terms of first ionization enthalpy values.
Statement II : $\text{S} > \text{Se} > \text{Te} > \text{Po} > \text{O}$ is the correct order in terms of the magnitude of electron gain enthalpy values.
In the light of the above statements, choose the correct answer from the options given below :
