Chapter 22 Carbon & Hydrocarbons
Diamond Graphite Fullerenes Delocalized electrons Organic compounds Catenation Hydrocarbons Isomers Structural formula Structural isomers Geometric isomers Saturated hydrocarbon Alkanes Cycloalkanes Alkyl groups Natural gas Petroleum Unsaturated hydrocarbons Alkynes Aromatic hydrocarbons benzene Chapter 22 Vocabulary
Diamond is a colorless, crystalline, solid form of carbon Graphite is a soft, black, crystalline form of carbon that is a fair conductor of electricity Fullerenes are dark colored solids made of spherically networked carbon atom cages. Delocalized electrons are electrons shared by more than two atoms Organic compounds covalently bonded compounds containing carbon, excluding carbonates and oxides. Catenation the covalent bonding of an element to itself to form chains or rings. Hydrocarbons are composed of only carbon and hydrogen; they are the simplest organic compounds. Compounds that have the same molecular formula but different structures are called isomers. Structural formula indicates the number and types of atoms present in a molecule and also shows the bonding arrangement of the atoms. Chapter 22 Vocabulary
Structural isomers are isomers in which the atoms are bonded together in different orders. Geometric isomers are isomers in which the order of atom bonding is the same but the arrangement of atoms in space is different. Saturated hydrocarbons are hydrocarbons in which each carbon atom in the molecule forms four single covalent bonds with other atoms. Hydrocarbons that contain only single bonds are alkanes. Cycloalkanes are alkanes in which the carbon atoms are arranged in a ring, or cyclic, structure. Alkyl groups are groups of atoms that are formed when one hydrogen atom is removed from an alkane molecule Natural gas is a fossil fuel composed primarily of alkanes containing one to four carbon atoms Petroleum is a complex mixture of different hydrocarbons that varies greatly in composition. Unsaturated hydrocarbons are hydrocarbons in which not all carbon atoms have four single covalent bonds. Chapter 22 Vocabulary
Chapter 22 Vocabulary • Structural isomers are isomers in which the atoms are bonded together in different orders. • Geometric isomers are isomers in which the order of atom bonding is the same but the arrangement of atoms in space is different. • Alkenes are hydrocarbons that contain double covalent bonds. • Hydrocarbons with triple covalent bonds are alkynes. • Aromatic hydrocarbons are hydrocarbons with six membered carbon rings and delocalized electrons • Benzene is the primary aromatic hydrocarbon
Alkanes and Aromatic Hydrocarbons Organic Compounds Bonding in Hydrocarbons Naming Alkanes Properties of Alkanes
Organic Chemistry and Hydrocarbons • _________ originally meant chemicals that came from ______________. • 1828 German chemist Friedrich Wohler synthesized urea in a lab • Today, organic chemistry is the chemistry of virtually all compounds containing the element ___________.
Friedrich Wohler 1800 – 1882 Used inorganic substances to synthesize urea, a carbon compound found in urine. This re-defined organic chemistry.
Organic Chemistry and Hydrocarbons • Over a million organic compounds, with numerous properties • Why so many? Carbon’s unique bonding ability! • Let’s start with the simplest of the organic compounds: Hydrocarbons
Organic Compounds • Contain _________________ • Have ______________ bonds • Have low _____________ points • Have low _______________ points • Burn in air (oxygen) • Are soluble in _____________ solvents • Form large ________________
Alkanes • Contain ______ and _________ only • Contain ____________ bonds C-C • Have _____ bonds to every carbon (C) atom • Are ________________
Alkanes Structural Formulas Show the bonds between each of the atoms H H H C H H C H H H CH4 - methane
Alkanes Structural Formulas H H Condensed Structural Formulas H C C H CH3 CH3 H H Ethane H H H H C C C H CH3 CH2 CH3 H H H Propane
Alkanes Structural Formulas H H H H C C C H H H H CH3 CH2 CH3 CH3CH2CH3 Structural Formula Condensed Structural Formula Condensed Formula
Alkanes Structural Formulas Examples: Condensed__________________ _____________ formula
Naming Alkanes Name # carbons Structural Formula ____ane 1 CH4 ____ane 2 CH3CH3 ____ane 3 CH3CH2CH3 ____ane 4 CH3CH2CH2CH3 ____ane 5 CH3CH2CH2CH2CH3
Naming Alkanes Name # carbons Structural Formula ___ane 6 CH3CH2CH2CH2CH2CH3 ____ane 7 CH3CH2CH2CH2CH2CH2CH3 ___ane 8 CH3CH2CH2CH2CH2CH2CH2CH3 ___ane 9 CH3 CH2 CH2CH2CH2CH2CH2CH2CH3 ___ane 10 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH3
Practice Problems A. What is the condensed formula for H H H H H C C C C H H H H H B. What is its molecular formula? C. What is its name?
Reactions of Alkanes Combustion alkane + O2 CO2 + H2O + heat Combustion In the Cell Metabolic oxidation is combustion C6H12 O6 + 6O2 6CO2 + 6H2O + heat glucose
Combustion Example Complete the combustion reaction for C3H8 + O2 + Balance your equation
Practice Problem Complete and balance the reaction for the complete combustion of C7H16
Alkanes and Aromatic Hydrocarbons Branched Alkanes Structural Formulas
Alkyl Groups Branches on carbon chains H H C CH3 _________ H H H H C C CH3CH2 _________ H H
Branched Alkanes CH3 CH3CHCH3 methyl groups CH3 CH3 CH3CHCH2CHCH3
Naming Branched Alkanes CH3 methyl branch CH3CH2CH2CHCH2CH3 6 5 4 3 2 1 Count
Naming Branched Alkanes CH3 methyl branch CH3CH2CH2CHCH2CH3 6 5 4 3 2 1 Count 3-Methylhexane on third C CH3 six carbon chain group
Naming Practice Problems A. CH3CH3 CH3CHCH2CHCH3 B. CH3 CH3 CH3CH2CHCH2CCH2CH3 CH3
Practice Problems Write a condensed structure for A. 3,4-dimethylheptane B. 2,2-dimethyloctane
Isomers • Same _____________ formula • Same ________ and ______ of atoms • Different ________________ of atoms • Also have different properties, such as b.p., m.p., and reactivity
Structural Isomers ___________________ are isomers in which the atoms are bonded together in different orders.
Geometric Isomers • ____________________ are isomers in which the order of atom bonding is the same but the arrangement of atoms in space is different.
Examples of Isomers The formula C4H10 has two different structures CH3 CH3CH2CH2CH3 CH3CHCH3 Butane 2-methylpropane When a CH3 is is used to form a branch, it makes a new isomer of C4H10.
Practice Problem Write 3 isomers of C5H12 and name each.
Practice Problems Write the structural formulas of 3 isomers that have the formula C5H12. Name each.
Alkanes and Aromatic Hydrocarbons Cycloalkanes Aromatic Hydrocarbons
Cycloalkanes _____________ CH2 CH2 CH2 _____________ CH2 CH2 CH2 CH2
More Cycloalkanes ____________ CH2 CH2 CH2 CH2 CH2 ____________ CH2 CH2 CH2 CH2 CH2 CH2
Naming Cycloalkanes with Side Groups Number of Naming side groups One Side group name goes in front of the cycloalkane name. Two or more Number the ring in the direction that gives the lowest numbers to the side groups.
Aromatic Compounds and Benzene ___________________ contain __________. Benzene, C6H6 , is represented as a ______ carbon ring with _____ double bonds. Two possible can be drawn to show benzene in this form.
Benzene Structure The structures for ______________ can also be written as a single structure where the alternating double bonds are written as a circle within the ring. Benzene structure
Aromatic Compounds in Nature and Health Many aromatic compounds are common in _____________ and in _____________.
Naming Aromatic Compounds Aromatic compounds are named with benzene as the parent chain. One side group is named in front of the name benzene. methylbenzene chlorobenzene (toluene)
Naming Aromatic Compounds When two groups are attached to benzene, the ring is numbered to give the lower numbers to the side groups. The prefixes ortho (1,2), meta (1,3-) and para (1,4-) arealso used.