Marked out of 4.00 Which of the following statement is NOT CORRECT about bond polarity?
a. All carbon-based compounds are covalently bonded and may be fully ionic. b. Separation of charge in a compound is a measurement of bond polarity. c. A compound’s polarity is dependent on the symmetry of the compound and electronegativity difference between atoms. d. Polar covalent is the intermediate type of bonding between two extremes.
The correct answer and explanation is:
The correct answer is: a. All carbon-based compounds are covalently bonded and may be fully ionic.
Explanation:
- Option a: “All carbon-based compounds are covalently bonded and may be fully ionic.”
This statement is NOT correct. While it is true that carbon-based compounds (such as organic compounds) are predominantly covalent in nature, they cannot be “fully ionic.” Covalent bonds involve the sharing of electrons between atoms, whereas ionic bonds involve the complete transfer of electrons. Carbon atoms have a relatively high electronegativity and are not likely to form ionic bonds under normal conditions. Carbon-based compounds may have polar covalent bonds, but they do not typically form ionic bonds because of the nature of the carbon atom itself. - Option b: “Separation of charge in a compound is a measurement of bond polarity.”
This statement is correct. Bond polarity arises due to the difference in electronegativity between the two atoms involved in the bond. When one atom is more electronegative than the other, it attracts electrons more strongly, creating a partial negative charge on that atom and a partial positive charge on the other. This separation of charge results in a dipole moment, which is a measurement of the bond’s polarity. - Option c: “A compound’s polarity is dependent on the symmetry of the compound and electronegativity difference between atoms.”
This statement is correct. The overall polarity of a molecule depends on the individual bond polarities and the geometry of the molecule. If a molecule has asymmetry in its shape (for example, in non-linear molecules like water), the individual dipoles do not cancel out, making the molecule polar. Additionally, a larger electronegativity difference between atoms generally leads to a more polar bond. - Option d: “Polar covalent is the intermediate type of bonding between two extremes.”
This statement is correct. Bonding can range from purely covalent to purely ionic, with polar covalent bonds being an intermediate type. In polar covalent bonds, electrons are shared unequally, leading to partial charges on the atoms involved.
In summary, option a is the only incorrect statement because carbon-based compounds are not ionic, and they do not “fully” become ionic in any circumstances.