Final answer:
D. a high melting point The polar covalent compound SO2 is likely to exhibit brittleness in the solid phase, and would not be expected to have high electrical conductivity, act as a strong electrolyte, or have a high melting point.
Step-by-step explanation:
The polar covalent compound SO2 is likely to exhibit brittleness in the solid phase. Substances with covalent bonding like SO2 are usually characterized by low to moderate melting and boiling points, and they do not conduct electricity well in the solid or liquid state.
They are generally more brittle in nature when in the solid phase. This is because the covalent bonds are directional and do not allow for the sort of free-flowing electrons that would convey electrical current or the malleability that allows substances to deform without breaking.
Given these characteristics, SO2 would not be expected to exhibit high electrical conductivity, act as a strong electrolyte, or have a particularly high melting point. Ionic compounds, not covalent ones, typically have higher melting points and can conduct electricity when molten due to the presence of free ions.