(b) When subjected to high pressure and heated, polyvinyl chloride converts to diamond. During this transformation which bonds are most likely to break first?

Verified step by step guidance

1. Identify the bonds present in polyvinyl chloride (PVC). PVC primarily contains C-H, C-C, and C-Cl bonds.
2. Refer to the provided table to find the bond energies for C-H, C-C, and C-Cl bonds. The bond energies are: C-H (414 kJ/mol), C-C (347 kJ/mol), and C-Cl (339 kJ/mol).
3. Compare the bond energies to determine which bond is the weakest. The bond with the lowest bond energy will break first.
4. From the bond energies, identify that the C-Cl bond has the lowest bond energy (339 kJ/mol) among the bonds in PVC.
5. Conclude that during the transformation of PVC to diamond under high pressure and heat, the C-Cl bonds are most likely to break first.

Key Concepts

Bond Energy

Bond energy is the amount of energy required to break a bond between two atoms in a molecule. It is a measure of the strength of the bond; higher bond energies indicate stronger bonds. In the context of the transformation of polyvinyl chloride to diamond, understanding bond energies helps identify which bonds are likely to break first under high pressure and temperature.

Types of Chemical Bonds

Chemical bonds can be classified into different types, including covalent, ionic, and metallic bonds. Covalent bonds, formed by the sharing of electrons, are particularly relevant here, as polyvinyl chloride primarily consists of carbon and chlorine atoms bonded covalently. The type of bond influences its energy and stability, which is crucial for predicting which bonds will break during the transformation process.

Thermodynamics of Reactions

Thermodynamics involves the study of energy changes during chemical reactions. When polyvinyl chloride is subjected to high pressure and heat, the energy input can overcome the bond energies, leading to bond breaking and reformation into a different structure, such as diamond. Understanding the thermodynamic principles helps in predicting the feasibility and direction of the transformation.