Question

which substance most likely has the highest boiling point? calcium chloride (cacl2), an ionic compound methanol (ch3oh), a polar covalent compound carbon tetrachloride (ccl4), a nonpolar covalent compound

Explanation:

Ionic compounds have strong electrostatic forces between ions. Polar covalent compounds have dipole - dipole forces and in some cases hydrogen - bonding. Nonpolar covalent compounds have only weak London dispersion forces. Stronger intermolecular forces require more energy to break, resulting in higher boiling points. Calcium chloride, an ionic compound, has stronger intermolecular forces compared to the covalent compounds given.

Answer:

calcium chloride ($CaCl_2$), an ionic compound