Melting Points (Gizmo) Questions and Answers Already Passed

Melting Points (Gizmo) Questions and Answers Already Passed In general, which type of compound tends to have the lowest melting point? A. Molecular Solids An unknown substance is a white solid at room temperature and has a melting point of 78 C. Which of the following substances is most likely to be the identity of the unknown sample? A. Naphthalene, a molecular solid with the formula C10H8 The following transition occurs at molecular level for a substance. What transition corresponds to this change in microscopic structure? C. Sublimation; the transition of a substance directly from the solid state to the gas state What is the most important reason that caffeine (C8H10N4O2) has a lower melting point than copper (II) chloride (CuCl2)? A. The intermolecular forces holding the caffeine molecules together are weaker than the ionic bonds in CuCl2. A petroleum refinery is producing the four products shown in the table. The table also shows the state of matter at room temperature of each of the substances. All of these compounds are molecular compounds consisting of only hydrogen and carbon. Which of the following products is likely to have the highest molecular weight? D. Paraffin wax