Question

Which among the following is ionic compound ?

• A. SnCl4
• B. PbF4
• C. CCl4
• D. SiCl4

Answer 1

Answer: (B)

PbF4

Answer 2

Ionic compounds are formed by electron transfer, typically between metals and non-metals. Covalent compounds involve electron sharing between non-metals or metalloids.

• SnCl₄, CCl₄, and SiCl₄ are all covalent compounds, characterized by low melting/boiling points and liquid states at room temperature. This is because Sn, C, and Si form bonds with chlorine primarily through sharing electrons, and Sn in +4 oxidation state exhibits significant covalent character due to high polarizing power.
• PbF₄ is an ionic compound. Although lead is in a high +4 oxidation state, which usually favors covalency, fluorine is the most electronegative element and has a very small, non-polarizable anion. This strong electronegativity difference and the difficulty in polarizing the fluoride ion lead to significant ionic character. PbF₄ is a high melting point solid, indicative of an ionic lattice.