$41.\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ is a common impurity found in refinery feedstock, which can lead to corrosion in equipment. $($a$)$ Sulfur $($b$)$ Oxygen $($c$)$ Nitrogen $($d$)$ Mercury

$42.$ The primary function of $\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ in petrochemical processes is to provide heat for various reactions. $($a$)$ Synthesis gas $($b$)$ Butylene $($c$)$ Acetylene $($d$)$ Hydrogen

$43.$ The production of $\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ involves the pyrolysis of hydrocarbons, resulting in the formation of carbon black and hydrogen. $($a$)$ Ethylene $($b$)$ Propylene $($c$)$ Acetylene $($d$)$ Butylene

$44.\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_$ is a common derivative of ethylene, used in the manufacturing of various plastics. $($a$)$ Ethanol $($b$)$ Polyethylene $($c$)$ Butadiene $($d$)$ Propane