Presentation on theme: "1) Hydrocarbon Rings 2) Hydrocarbons From Earth’s Crust."— Presentation transcript:
1) Hydrocarbon Rings 2) Hydrocarbons From Earth’s Crust
* Beta-carotene is an important nutrient in carrots that also gives carrots their orange color. The hydrocarbon skeleton of beta- carotene contains hydrocarbon rings. You will learn about hydrocarbon rings and the properties of compounds formed from these rings.
* Within some hydrocarbons… they contain a chain of carbons that have formed a ring. * Cyclic Hydrocarbons: hydrocarbons that contain a hydrocarbon ring. * Predict how a hydrocarbon could form a ring…. Say butane or pentane….
* Three Ways to Represent Cyclic Hydrocarbons
* The simplest is a 3 ring hydrocarbon. * Rings containing up to 20 carbon atoms are found in nature. * The most abundant are rings that contain 5 or 6 carbons.
* These compounds are responsible for the aromas of spices such as vanilla, clove, cinnamon, and ginger. * They are named this because of the pleasant aromas they give off * NOT ALL aromatic compounds have an aroma. Though.
* Any compound that contains a benzene ring is an aromatic compound. * Benzene Basic Structure: In a benzene molecule, the bonding electrons between carbon atoms are shared evenly around the ring.
* What is different about these two benzenes? * Benzene can be shown as switching, or resonating, between two arrangements of alternating double and single bonds.
* If there are two (or more) equally valid structures for a molecule, resonance occurs. * Benzene and other molecules that have resonance are VERY stable. More stable than molecules that do not have resonance. * Show the resonance of Benzene…
* Compounds with a substituent on a benzene ring are named as a derivative of benzene. When benzene is a substituent, it is called a phenyl group.
The molecules of many dyes include benzene rings.
* 1) Natural Gas * 2) Petroleum * 3) Coal
* Natural gas is an important source of alkanes and aliphatic carbons of low molar mass. * Aliphatic Carbons contain no benzene rings. * The most important component of natural gas, methane, burns with a clean, hot flame. * Other common: propane and butane (grills and lighters)
* More complex hydrocarbons found in petroleum than in natural gas. * It contains MANY types that need to be separated for it to be useful. * We can refine it by distilling it into fractions according to the boiling points of the hydrocarbons. (See next slide) * Next, we use cracking where hydrocarbons are broken down…. https://www.youtube.com/watch?v=Xsqlv4rWnEg
* Coal is classified by its carbon content and hardness. * Hardness of coal tends to increase with higher carbon content. * Lignite ~50% carbon * Bituminous 70–80% carbon * Anthracite >80% carbon
* Coal consists largely of condensed aromatic compounds of extremely high molar mass.
* Use this time to complete your Chapter 22 Section Assessments. * Completed Labs are due today. Turn those in by the end of class.