If you are referring to first question of the section review for chapter 6.1 in the Addison-Wesley chemistry book, there is a table on the same page as the question listing the differences.
NaCo+2
Ionic compounds are generally made up of nonmetals and metals, while molecular compounds are normally made up of nonmetals only.
Ionic compounds contain ionic compounds whereas molecular compounds contain covalent bonds in their molecules.
In molecular compounds, atoms are joined by covalent bonds, while in ionic compounds, they are joined by ionic bonds.
Ionic
Many ionic compounds exist as crystals but covalent compounds as molecules (there are exceptions as diamond though). Ionic compounds would be good electrical conductors unlike molecular compounds.
Ionic compounds are generally made up of nonmetals and metals, while molecular compounds are normally made up of nonmetals only.
Ionic compounds contain ionic compounds whereas molecular compounds contain covalent bonds in their molecules.
In molecular compounds, atoms are joined by covalent bonds, while in ionic compounds, they are joined by ionic bonds.
Ionic
Many ionic compounds exist as crystals but covalent compounds as molecules (there are exceptions as diamond though). Ionic compounds would be good electrical conductors unlike molecular compounds.
Ionic compounds have higher melting and boiling points than molecular compounds do. The electronegativity difference in ionic compounds makes their bond much stronger.
Ionic compounds conduct electricity while molecular compounds do not
Molecular. (Molecular and covalent compounds are the same).
Water can dissolve some ionic compounds as well as some molecular compounds because of its polarity. It is polar enough to dissolve ionic compounds into their ions. Water does not dissolve molecular compounds by breaking covalent bonds, but through intermolecular forces.
It is ionic, since Na (sodium) is one of the Alkali metals. Here's a tip: molecular compounds involve non-metal substances, whereas ionic compounds involve metal substances.
Molecular compounds tend to have lower melting points.
Molecular (covalent) compounds are not dissociated in water.