Which statement best describes the properties of ionic compounds

Most properties of ionic compounds are based on the strength of the ionic bonds. Ionic bonds are the strongest bonds between atoms (compared with covalent bonds), so that implies that the ionic compounds will be solid and form crystals at room temperature, will have high melting and boiling points, will be hard, rigid and brittle, will dissolve into ions (cations and anions) in polar solvents, and their solutions will conduct electricity.

2Fe + O₂ > 2FeO

8 mol Fe produce

8 mol Fe * 2 mol FeO / 2 mol Fe = 8 mol FeO

Mass of FeO = 8 mol FeO * 71.85 g/mol = 574.8 grams FeO

Explanation:

Having 8 mol of Iron means 8 moles of iron oxide can be produced. Each mole of iron oxide has a molecular weight of 71.85 grams. Therefore, 8 moles of iron oxide should weight 574.8 grams.