22. Select two substances that do not have a molecular crystal lattice: 1) KNO_(3) 2) NH_(3) 3) BN 4) SO_(3) 5) C_(5)H_(12) Answer (score: 1)

The correct answer is 2) and 5) .Molecular crystal lattices are formed by molecules held together by relatively weak intermolecular forces, such as van der Waals forces or hydrogen bonds. In this case, and are both molecular compounds, meaning they consist of discrete molecules rather than a lattice of ions or covalently bonded atoms. , or ammonia, is a simple molecule composed of one nitrogen atom bonded to three hydrogen atoms. It forms a molecular crystal lattice due to the weak hydrogen bonds between the molecules. , or pentane, is a hydrocarbon molecule composed of five carbon atoms bonded to twelve hydrogen atoms. It also forms a molecular crystal lattice due to the weak van der Waals forces between the molecules.On the other hand, , BN, and are all ionic or covalent compounds that form crystal lattices. , or potassium nitrate, is an ionic compound that forms a lattice of potassium ions and nitrate ions. BN, or boron nitride, is a covalent compound that forms a lattice of boron atoms and nitrogen atoms. , or sulfur trioxide, is a covalent compound that forms a lattice of sulfur atoms and oxygen atoms.