$55.\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ is a common petrochemical derivative used in the manufacturing of various plastics, while $\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ is primarily used in the production of synthetic rubber. $($a$)$ Polyethylene $($b$)$ Butadiene $($c$)$ Ethanol $($d$)$ Propylene

$56.$ The main application of $\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ in the petrochemical industry is the production of $\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ for fertilizers and various chemical processes. $($a$)$ Synthesis gas $($b$)$ Hydrogen $($c$)$ Ammonia $($d$)$ Ethylene

$57.$ The production of $\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ involves the pyrolysis of hydrocarbons, resulting in the formation of $\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ and hydrogen. $($a$)$ Ethylene $($b$)$ Propylene $($c$)$ Acetylene $($d$)$ Butylene

$58.\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ is a common impurity found in refinery feedstock, which can lead to corrosion in equipment, while $\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ is another impurity that reduces the efficiency of catalytic processes. $($a$)$ Sulfur $($b$)$ Oxygen $($c$)$ Nitrogen $($d$)$ Mercury