The order of the boiling points for the hydrogen halides, except for HF, is
HI > HBr > HCl. The reason for this order can be attributed to
a) the relative covalent bond strengths.
b) differences in hydrogen bonding.
c) differences in dipole-dipole attractions.
d) differences in London forces.
e) differences in dipole/induced dipole interactions
Please help! cant decide between A or D
It's D.
To determine the reason for the observed order of boiling points for the hydrogen halides (HI > HBr > HCl), we need to consider the nature of intermolecular forces acting between the molecules. This will help us identify the correct answer choice between option a) the relative covalent bond strengths, and option d) differences in London forces.
The boiling point of a substance is determined by the strength of intermolecular forces. The stronger the intermolecular forces, the higher the boiling point.
Option a) pertains to covalent bond strengths. However, the boiling points of the hydrogen halides are not solely determined by the strength of their covalent bonds. All hydrogen halides (HF, HCl, HBr, HI) have similar covalent bonds in terms of bond length and strength.
Option d) refers to London forces, also known as dispersion forces. London forces are the intermolecular forces between all molecules, including nonpolar molecules. These forces arise due to temporary fluctuations in electron distribution that create temporary dipoles, resulting in weak attractions between neighboring molecules.
The order of boiling points observed for the hydrogen halides (HI > HBr > HCl) can be attributed to the differences in London forces. As we move down the group in the periodic table from HCl to HBr to HI, the number of electrons increases, leading to a greater possibility for temporary fluctuations in electron distribution. Consequently, the strength of the London forces increases, resulting in higher boiling points.
Therefore, the correct answer is d) differences in London forces.