$8.$ Examine the significance of isomerization in the production of petroleum products. How does isomerization affect the properties of hydrocarbons, such as their boiling points, viscosity, and combustion characteristics?

$9.$ Investigate the diverse range of petroleum products derived from refining processes, including naphtha, kerosene, diesel oil, and lubricants. Discuss their respective uses, properties, and market demand in various industrial sectors$.$