Petroleum: Breaking and Making Bonds

Petroleum A: Petroleum - What is it?

What is Petroleum?  Crude Oil, Black Gold, Texas Tea  Thin as water, thick as tar.  Cannot be used in its natural form - it must be refined.  Hydrocarbons - result from refining petroleum.  Are molecular compounds that contain atoms of elements of carbon and hydrogen only.  Crude oil is made of dozens of hydrocarbons.  Crude Oil, Black Gold, Texas Tea  Thin as water, thick as tar.  Cannot be used in its natural form - it must be refined.  Hydrocarbons - result from refining petroleum.  Are molecular compounds that contain atoms of elements of carbon and hydrogen only.  Crude oil is made of dozens of hydrocarbons.

Uses for Petroleum  Fuel  CD’s  Sports Equipment  Clothing  Auto Parts  Medication  Artificial Limbs  84% burned as fuel, 7% medications/plastics, 9% lubricant, road paving materials, etc.  Fuel  CD’s  Sports Equipment  Clothing  Auto Parts  Medication  Artificial Limbs  84% burned as fuel, 7% medications/plastics, 9% lubricant, road paving materials, etc.

What happens to petro?  Burning petroleum = combustion reaction (chemical reaction)  Hydrocarbons become carbon dioxide and water vapor - ALWAYS!!  C 8 H 18 + O 2  CO 2 + H 2 O  Petroleum is a nonrenewable resource.  Burning petroleum = combustion reaction (chemical reaction)  Hydrocarbons become carbon dioxide and water vapor - ALWAYS!!  C 8 H 18 + O 2  CO 2 + H 2 O  Petroleum is a nonrenewable resource.

Distribution of petroleum  See page 214, figure 3.4  Petroleum is not distributed evenly around the world.  Petroleum is not consumed evenly around the world  See page 214, figure 3.4  Petroleum is not distributed evenly around the world.  Petroleum is not consumed evenly around the world

Petroleum Refining  Crude oil can be “distilled.”  More complicated. When crude oil is distilled it does not neatly separate into the products we use. Rather, it separates into different mixtures of chemicals called fractions. This process is known as fractional distillation  This happens in a tower called a fractioning tower.  Crude oil can be “distilled.”  More complicated. When crude oil is distilled it does not neatly separate into the products we use. Rather, it separates into different mixtures of chemicals called fractions. This process is known as fractional distillation  This happens in a tower called a fractioning tower.

Petroleum Refining  First, crude is heated (not burned) to 400  C in a furnace.  Second, hot crude oil is pumped into the fractioning tower (over 100 ft high). The tower has trays that collected the different fractions.  First, crude is heated (not burned) to 400  C in a furnace.  Second, hot crude oil is pumped into the fractioning tower (over 100 ft high). The tower has trays that collected the different fractions.

Petroleum Refining  Some of the lighter molecules with lower boiling points vaporize and rise to the top where they are collected  Molecules with higher boiling points are heated hotter so they will vaporize.  The heaviest molecules with highest boiling points never vaporize  Some of the lighter molecules with lower boiling points vaporize and rise to the top where they are collected  Molecules with higher boiling points are heated hotter so they will vaporize.  The heaviest molecules with highest boiling points never vaporize

Distillation lab setup

Petroleum’s Molecules  Light Molecules: small carbon chain (1-4 C’s), low melting point (40  C).  Heavy Molecules: large or larger carbon chain (5-20 C’s), high melting points  Intermolecular forces - forces of attraction between molecules.  Light molecules have weak IM forces - they are gases  Heavy molecules have strong or stronger IM forces - they are liquids, or very thick liquids (tar).  HW: pg 220, A.5 “Hydrocarbon Boiling Points”  Light Molecules: small carbon chain (1-4 C’s), low melting point (40  C).  Heavy Molecules: large or larger carbon chain (5-20 C’s), high melting points  Intermolecular forces - forces of attraction between molecules.  Light molecules have weak IM forces - they are gases  Heavy molecules have strong or stronger IM forces - they are liquids, or very thick liquids (tar).  HW: pg 220, A.5 “Hydrocarbon Boiling Points”

Chemical Bonding  Organic Chemistry - consists of hydrocarbons and their derivatives.  Called organic compounds - once thought to only come from living things - not true.  Hydrocarbons have a carbon chain - a chain of carbon with hydrogen attached to the carbons.  Organic Chemistry - consists of hydrocarbons and their derivatives.  Called organic compounds - once thought to only come from living things - not true.  Hydrocarbons have a carbon chain - a chain of carbon with hydrogen attached to the carbons.

Hydrocarbons - Carbon Chain

Chemical Bonding - Electron Shells  Review: Protons and neutrons are in the nucleus; electrons orbit the nucleus  The electrons have a specific arrangement.  Energy levels - electrons are located in these large 3-D areas around the nucleus.  Each energy level can hold a specific amount of electrons  1st energy level = maximum of 2 electrons  2nd energy level = maximum of 8 electrons  3rd energy level = maximum of 18 electrons  Review: Protons and neutrons are in the nucleus; electrons orbit the nucleus  The electrons have a specific arrangement.  Energy levels - electrons are located in these large 3-D areas around the nucleus.  Each energy level can hold a specific amount of electrons  1st energy level = maximum of 2 electrons  2nd energy level = maximum of 8 electrons  3rd energy level = maximum of 18 electrons

Electron Shells

Electron Shells and Noble Gases  Noble gases are known to be very stable elements  They don’t want to react with anything  The most stable position an atom can be in is when its outermost energy level is filled.  Noble gases have a filled outer energy level  He = 2 electrons. These 2 electrons fill up the energy level that they are in.  So, He is stable  Noble gases are known to be very stable elements  They don’t want to react with anything  The most stable position an atom can be in is when its outermost energy level is filled.  Noble gases have a filled outer energy level  He = 2 electrons. These 2 electrons fill up the energy level that they are in.  So, He is stable

Electron Shells and Noble Gases

 Neon is a noble gas AND very stable  10 electrons  1st energy level is filled (2 electrons)  2nd energy level is filled (8 electrons)  10 electrons TOTAL with 2 energy levels filled  Neon is a noble gas AND very stable  10 electrons  1st energy level is filled (2 electrons)  2nd energy level is filled (8 electrons)  10 electrons TOTAL with 2 energy levels filled

Electron Shells and Noble Gases Neon: 10 Protons 10 Electrons

Electron Shells and ions  Sodium has 11 electrons  Sodium wants 10 electrons to be stable like Neon.  Sodium will lose 1 electron (when it reacts) becoming an ion.  Na +1 (11p, 10 e)  Sodium has 11 electrons  Sodium wants 10 electrons to be stable like Neon.  Sodium will lose 1 electron (when it reacts) becoming an ion.  Na +1 (11p, 10 e)

 Fluorine has 9 electrons  Fluorine wants 10 electrons to be stable like Neon  Fluorine will gain 1 electron (when it reacts) becoming an ion.  F -1 (9p, 10e)  Fluorine has 9 electrons  Fluorine wants 10 electrons to be stable like Neon  Fluorine will gain 1 electron (when it reacts) becoming an ion.  F -1 (9p, 10e)

Covalent Bonds  A covalent bond is made by sharing electrons (not gaining or losing like you just learned)  By sharing electrons atoms can fill their energy levels.  Hydrogen has only one electron - it wants two.  H will share with another element to fill its energy level  A covalent bond is made by sharing electrons (not gaining or losing like you just learned)  By sharing electrons atoms can fill their energy levels.  Hydrogen has only one electron - it wants two.  H will share with another element to fill its energy level

Covalent bonds - Hydrogen

Covalent Bonds - Carbon  Carbon is very important  It forms the backbone of all hydrocarbons  Carbon forms covalent bonds with hydrogen  C will share four electrons with other elements (hydrogen)  Single covalent bond - is bond shared between one pair of electrons  Carbon is very important  It forms the backbone of all hydrocarbons  Carbon forms covalent bonds with hydrogen  C will share four electrons with other elements (hydrogen)  Single covalent bond - is bond shared between one pair of electrons

Covalent bonds - Carbon

Electron-dot formulas  Electron-dot formulas - shows the electrons that involved in a chemical bond (chemical reaction)  Maximum number = 8 electrons (valence electrons!!!)  H is exception = only 2  Electron-dot formulas illustrates covalent bonding  Valence electrons = the group number OR the group number  Electron-dot formulas - shows the electrons that involved in a chemical bond (chemical reaction)  Maximum number = 8 electrons (valence electrons!!!)  H is exception = only 2  Electron-dot formulas illustrates covalent bonding  Valence electrons = the group number OR the group number - 10.

Electron-dot and structural formulas  Structural formula - show a covalently bonded molecule  2-D  Each line represents a bond = 2 electrons  Steps to drawing structural formulas: 1.Draw electron dot formulas for all atoms. 2.Position the elements around the atom that can form the most bonds (most often C) 3.Connect the dots  Structural formula - show a covalently bonded molecule  2-D  Each line represents a bond = 2 electrons  Steps to drawing structural formulas: 1.Draw electron dot formulas for all atoms. 2.Position the elements around the atom that can form the most bonds (most often C) 3.Connect the dots

Do the following for Homework 1.C 5 H 12 2.SiCl 4 3.PI 3 4.CBr 2 F 2 1.C 5 H 12 2.SiCl 4 3.PI 3 4.CBr 2 F 2 5. NaCl 6. C 8 H C 2 H 4 Cl 2 5. NaCl 6. C 8 H C 2 H 4 Cl 2

Alkanes  Alkanes:  Hydrocarbon  All single bonds  Pattern C x H 2x+2  Octane: 8 C’s  C 8 H 18  MEMORIZE ALKANES ON PAGE NAME, MOLECULAR FORMULA, AND CONDENSED FORMULA  Alkanes:  Hydrocarbon  All single bonds  Pattern C x H 2x+2  Octane: 8 C’s  C 8 H 18  MEMORIZE ALKANES ON PAGE NAME, MOLECULAR FORMULA, AND CONDENSED FORMULA

Alkanes  Example of a molecular formula:  CH 4  C 2 H 6  Example of a condensed formula:  CH 3 CH 2 CH 2 CH 2 CH 3  Trends in alkane boiling points: the longer the chain, the higher the boiling point.  HW: p A.8 “Trends in Alkane Boiling Points. Use graph paper and answer the questions on the back.  Example of a molecular formula:  CH 4 C2H6C2H6  Example of a condensed formula:  CH 3 CH 2 CH 2 CH 2 CH 3  Trends in alkane boiling points: the longer the chain, the higher the boiling point.  HW: p A.8 “Trends in Alkane Boiling Points. Use graph paper and answer the questions on the back.

Alkanes  So far, all we have seen has been “straight-chain alkanes”  Branched alkanes.  2-methyl, propane  So far, all we have seen has been “straight-chain alkanes”  Branched alkanes.  2-methyl, propane

Alkanes  Structural Isomers - molecules that have identical formulas but different arrangements of atoms.  C 5 H 12   Structural Isomers - molecules that have identical formulas but different arrangements of atoms.  C 5 H 12 

Boiling Points of Branched alkanes  The more branches an isomer has the lower the boiling point.