Of the choices below, which one is not an ionic compound? A) PCl5
B) MoCl6
C) RbCl
D) PbCl2
E) NaCl

PCl₅ is not an ionic compound. Ionic or electrovalent compounds are formed

through the transfer of electrons in a chemical reaction. Metals and non-

metals mostly form ionic compounds.

Covalent bonding on the other involves the sharing of electrons between

two elements. Non-metals are mostly involved in this type of reaction.

PCl₅ possesses a covalent bond and not ionic as electrons are shared

between two non metals  which are phosphorus and chlorine.

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is not an ionic compound.

Explanation:

An ionic compound is defined as the compound which is formed when electron gets transferred from one atom to another atom.  The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.

Thus , , and are all ionic compounds.

Covalent compound is defined as the compound which is formed by the sharing of electrons between the atoms forming a compound. These are usually formed when two non-metals react.

Thus is a covalent compound as both Phosphorous and chlorine are non metals.

c) should be the answer.

yes the answer is total mass in unchanged   : )