1) prepare down the characteristics of petroleum refining. What do you mean by catalytic reforming? Describe how plastics are categorized? prepare down the methods in which polymerization takes place? prepare down the name of three synthetic fibers. prepare down the ex of polyester. prepare down the name of three synthetic rubbers.

2) For what kind of materials in vegetable tanning is used? Categorize the dyes and describe them in detail. prepare down the name of two tanning processes in leather industry.