Production of Materials Flashcards
Ethylene is produced from crude oil, what is crude oil and where is it found?
Crude oil (or peteroleum) is a naturally occurring, yellow-to-black liquid found in geological formations beneath the Earth’s surface. It consists of hydrocarbons of various molecular weights.
How is ethylene manufactured and what main types of manufacturing processes are used today?
Ethylene is manufacted from the fractional distilation (cracking) of crude oil (breaking long chain hydrocarbons into smaller ones like ethylene).
Main manufacturing processes: Steam and Catalytic cracking
Explain catalytic and steam cracking as well as the advantages and disadvantages of both.
STEAM CRACKING: Steam cracking is a petrochemical process in which saturated (one bond) hydrocarbons are broken down into smaller, often unsaturated (double bond), hydrocarbons. HIGH TEMPERATURES (700C - 900C) and HIGH PRESSURES. ABSENCE OF OXYGEN.
CATALYTIC CRACING: Same process, long hydrocarbons are cracked into smaller ones. LOWER TEMPERATURES (500C - 600C) and LOWER PRESSURES. DONE WITH THE PRESENCE OF A CATALYST = zeolyte. ABSENCE OF AIR. The catalyst weakens the covalent bonds between molecules thus requires less energy to break apart (which is why you dont need as high temp. and pressure).
Why is ethylene so reactive? Furthermore, why is a double bond more reacive than a single bond?
Ethylene contains a double bond between carbon atoms (C=C).
A double bond is more reactive then a single bond because the double bond is physically “further away” from the two atoms. Which makes it easier for other molecules to react and “take or give” electrons
RECAP: A single bond contains one sigma bond. A double bond contains one sigma bond and one pi bond. Here are what orbitals look like in a double bond (picture). For more info on orbitals: https://www.youtube.com/watch?v=9E3QaRxqXZc
What usefulness does the high reactivity of the double bond in ethylene present interms of production of materials
Ethylene because of ith high reactivity of its double bond can easily be made into polymers or reacted with other chemicals to form other polymers. Making plastic products such as food wraps, milk bottles, garbage bins and SD cases.
