To determine which substance most likely has the highest boiling point, we need to understand the nature of the three compounds and the types of intermolecular forces present in each.
1. Calcium chloride [tex]\(\left( CaCl_2 \right)\)[/tex]:
- Type of Compound: Ionic compound.
- Intermolecular Forces: Ionic bonds.
- Characteristics: Ionic bonds are very strong due to the electrostatic attraction between the positively charged calcium ions ([tex]\(Ca^{2+}\)[/tex]) and the negatively charged chloride ions ([tex]\(Cl^{-}\)[/tex]). These strong ionic bonds result in very high boiling points.
2. Methanol [tex]\(\left( CH_3OH \right)\)[/tex]:
- Type of Compound: Polar covalent compound.
- Intermolecular Forces: Hydrogen bonds, dipole-dipole interactions.
- Characteristics: Methanol has a moderate boiling point due to hydrogen bonding between the oxygen atom (with its lone pair of electrons) and the hydrogen atoms of other methanol molecules. While these bonds are strong, they are weaker than ionic bonds.
3. Carbon tetrachloride [tex]\(\left( CCl_4 \right)\)[/tex]:
- Type of Compound: Nonpolar covalent compound.
- Intermolecular Forces: Van der Waals (dispersion) forces.
- Characteristics: As a nonpolar molecule, carbon tetrachloride has relatively weak dispersion forces. These forces are the weakest among the three types of intermolecular forces considered here, leading to lower boiling points compared to ionic or hydrogen-bonded compounds.
Considering these types of intermolecular forces and their strengths, the compound with the strongest intermolecular forces typically has the highest boiling point. Ionic bonds in calcium chloride are stronger than both hydrogen bonds in methanol and van der Waals forces in carbon tetrachloride.
Therefore, the substance most likely to have the highest boiling point is calcium chloride [tex]\(\left( CaCl_2 \right)\)[/tex].
