Chemistry

• In a combustion reaction, a substance reacts with oxygen to produce heat and light.
• Organic compounds contain carbon, except carbon dioxide and carbonates
• Hydrocarbons contain only hydrogen and carbon, come from crude oil which is a mixture of many different hydrocarbons and is refined to separate the mixture
• Two groups of organic compounds are aliphatic and aromatics
• Carbon has the ability to form 4 bonds, resulting in structures like straight chains, branched, or ring structures
• Alkanes are hydrocarbons with only carbon to carbon single bonds
• The general formula of an alkane is CnH2n+2
• Alkyl groups are branches off the main hydrocarbon chain
• To name alkanes, determine the longest continuous chain of carbons (parent chain) and number the carbons to locate branches
• If the branch has more than 2 carbons, use n-normal, iso, s-secondary, t-tertiary naming
• Name the compound by putting branches in alphabetical order, separating numbers with commas and numbers and letters with hyphens
• Structural isomers have the same formula but different structures due to branching
• Cyclic hydrocarbons have a closed ring structure, with 'cyclo' added in front of the parent chain name
• Example: Pentane (C5H12)
• Simple alkene: hydrocarbon with one carbon-to-carbon double bond
• General formula: CnH2n
• Names end in -ene
• Must indicate the location of the double bond with the lowest possible number
• Simple alkyne: hydrocarbon with one carbon-to-carbon triple bond
• General formula: CnH2n-2
• Names end in -yne
• Must indicate the location of the triple bond with the lowest possible number
• Naming rules for branched chain alkenes and alkynes are the same as alkanes, but the location of the double/triple bond takes precedence for numbering
• If alkene or alkyne has more than one double/triple bond, use prefixes (di-, tri-, etc.) and numbers to indicate presence and locations
• Example: 2-methyl-1,3-pentadiene
• Cis-Trans (Geometric) Isomers
• Result from the presence of a double bond
• Also known as geometric isomers
• Cis-trans isomers occur when different groups of atoms are arranged around the double bond
• Double carbon-carbon bond remains fixed and does not rotate
• General rules for determining cis-trans isomers:
• Each carbon in the C=C double bond must be attached to two different groups
• In a cis isomer, the two larger groups are attached to each C=C double bond on the same side
• In a trans isomer, the two larger groups are attached to each C=C on opposite sides
• Cis-trans isomers have different physical and chemical properties compared to each other
• Cis-trans isomers occur when different groups of atoms are arranged around a double bond
• The double carbon-carbon bond remains fixed and does not rotate
• To have a cis-trans (geometric) isomer, each carbon in the C=C double bond must be attached to two different groups
• In a cis isomer, the two larger groups are attached to each C=C double bond on the same side
• In a trans isomer, the two larger groups are attached to each C=C on opposite sides