To understand how the boiling points of [tex]\( \text{H}_2 \)[/tex], [tex]\( \text{F}_2 \)[/tex], and HF compare, we need to consider their molecular structures and the intermolecular forces involved.
1. Molecular Structure & Intermolecular Forces:
- [tex]\( \text{H}_2 \)[/tex]: Hydrogen molecule is nonpolar and experiences weak London dispersion forces.
- [tex]\( \text{F}_2 \)[/tex]: Fluorine molecule is also nonpolar and similarly experiences weak London dispersion forces.
- HF: Hydrogen fluoride is a polar molecule. Due to the significant electronegativity difference between hydrogen (H) and fluorine (F), HF molecules experience strong hydrogen bonding, a much stronger intermolecular force compared to the London dispersion forces in [tex]\( \text{H}_2 \)[/tex] and [tex]\( \text{F}_2 \)[/tex].
2. Boiling Points:
- The boiling point of a substance is higher when the intermolecular forces are stronger because more energy is required to separate the molecules into a gaseous state.
- As HF experiences strong hydrogen bonding, it will have a higher boiling point.
- Both [tex]\( \text{H}_2 \)[/tex] and [tex]\( \text{F}_2 \)[/tex] are nonpolar and only have weak London dispersion forces, resulting in lower boiling points.
3. Comparison:
- The boiling point of HF ([tex]\(\text{hydrogen fluoride}\)[/tex]) is higher than the boiling point of [tex]\( \text{H}_2 \)[/tex] (hydrogen) due to the presence of strong hydrogen bonds in HF.
- Similarly, the boiling point of HF is higher than the boiling point of [tex]\( \text{F}_2 \)[/tex] (fluorine) for the same reason.
Therefore, based on the intermolecular forces and molecular structures:
The boiling point of HF is higher than the boiling point of [tex]\( \text{H}_2 \)[/tex], and it is higher than the boiling point of [tex]\( \text{F}_2 \)[/tex].
