Textbook Question
(a) Rank the following bonds in terms of the strength of their bond dipole (1 = weakest, 6 = strongest).
(b) Which carbon has the largest δ⁺ ?
C―F, C―Br, C―I, C―H, C―C, C―Cl
1270
views
1. A Review of General Chemistry
Electronegativity
6:15 minutesProblem 14
Textbook Question
After examining the potential maps for LiH, HF, and H2, answer the following questions:
<IMAGE>
a. Which compounds are polar?
b. Why does LiH have the largest hydrogen?
c. Which compound has the hydrogen that would be most apt to attract a negatively charged molecule?
Verified step by step guidance1
Examine the molecular potential maps provided for LiH, HF, and H2. The maps show regions of electron density, with red indicating areas of high electron density and blue indicating areas of low electron density. Polar molecules will exhibit an uneven distribution of electron density.
Determine which compounds are polar by analyzing the maps. LiH and HF show a clear separation of charge, with one side of the molecule being more electron-rich (red) and the other side being electron-poor (blue). H2, on the other hand, has a uniform electron density distribution, indicating it is nonpolar.
Consider why LiH has the largest hydrogen. Lithium is less electronegative than hydrogen, causing the electron density to shift toward hydrogen. This results in hydrogen appearing larger in the potential map due to its increased electron density.
Identify which compound has the hydrogen most likely to attract a negatively charged molecule. HF has the most electronegative atom (fluorine), which pulls electron density away from hydrogen, leaving hydrogen with a partial positive charge. This makes the hydrogen in HF the most apt to attract a negatively charged molecule.
Summarize the findings: LiH and HF are polar, while H2 is nonpolar. LiH has the largest hydrogen due to electron density shifting toward it. The hydrogen in HF is the most likely to attract a negatively charged molecule due to its partial positive charge.
Verified video answer for a similar problem:This video solution was recommended by our tutors as helpful for the problem above
Video duration:
6mKey Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Polarity of Molecules
Polarity in molecules arises from the distribution of electrical charge, leading to regions of partial positive and negative charges. This occurs due to differences in electronegativity between atoms, causing uneven sharing of electrons. Polar molecules, like HF, have a significant dipole moment, while nonpolar molecules, such as H2, have an even distribution of charge.
Recommended video:
Guided course
2:04
Molecular Polarity
Hydrogen Bonding
Hydrogen bonding is a strong type of dipole-dipole interaction that occurs when hydrogen is covalently bonded to highly electronegative atoms like fluorine, oxygen, or nitrogen. In the context of LiH, the presence of lithium and its ionic character contributes to the strength of the hydrogen bond, making it significant in determining the compound's properties, including its size and reactivity.
Recommended video:
Guided course
00:48The definition of hydrogenation.
Attraction to Negatively Charged Molecules
The ability of a hydrogen atom to attract negatively charged molecules is influenced by its partial positive charge in polar compounds. In HF, the hydrogen is highly polarized due to fluorine's electronegativity, making it more likely to interact with negatively charged species. This characteristic is crucial for understanding reactivity and interactions in chemical systems.
Recommended video:
Guided course
01:34Calculating formal and net charge.
Related Videos
Related Practice