chem 30 ochem
Why is carbon essential to life?
Carbon can form an almost infinite variety of compounds, including sugars, proteins, and DNA.
How many valence electrons does carbon have?
Carbon has 4 valence electrons.
What types of bonds can carbon form?
Four single bonds, two double bonds, a double and two singles, or a triple and a single.
What makes carbon’s bonds strong?
Its small size keeps valence electrons close to the nucleus.
What structure does carbon typically form instead of C₂ molecules?
Long, stable chains (polymers).
What theory did Wöhler disprove by synthesizing urea?
Vitalism – the belief that organic compounds couldn't be lab-made.
What defines an organic compound?
A compound containing carbon (excluding oxides and carbonates).
What are hydrocarbons?
Organic molecules made only of carbon and hydrogen.
Why are hydrocarbons nonpolar?
They contain only carbon-carbon and carbon-hydrogen bonds, both of which are nonpolar.
Properties of hydrocarbons?
Nonpolar, poor conductors, low density, low melting/boiling points, insoluble in water.
What are fossil fuels made of?
Hydrocarbons from ancient plant/animal remains.
General formula for alkanes?
CnH₂n+2
What are saturated hydrocarbons?
Alkanes—hydrocarbons with only single bonds and the maximum number of hydrogen atoms.
How are straight-chain alkanes named?
Root (carbon count) + “-ane”.
What’s a branched alkane?
An alkane with at least one carbon bonded to more than 2 other carbon atoms.
What is an alkyl group?
A branched substituent group derived from alkanes, named with “-yl”.
How do you name branched alkanes?
Find parent chain, number it, name branches, use prefixes (di-, tri-, etc.), arrange alphabetically.
General formula for alkenes?
CnH₂n
How are alkenes named?
Root (carbon count) + “-ene”; number to show location of double bond.
Naming branched alkenes?
Use longest chain with the double bond as the parent; number from double bond end.
What is a diene or triene?
Alkenes with 2 or 3 double bonds, respectively.
General formula for alkynes?
CnH₂n-2
How are alkynes named?
Same as alkenes but suffix is “-yne”; number to show location of triple bond.
What are isomers?
Compounds with the same molecular formula but different structures.
What happens to the number of isomers as carbon atoms increase?
The number of possible isomers increases.
What is an alcohol?
A hydrocarbon where one or more H atoms are replaced by a hydroxyl group (–OH).
General formula for alcohols?
R–OH
How are alcohols named?
Add “-ol” to the hydrocarbon name and use a number to indicate OH position.
How do you use commas and dashes in naming hydrocarbons?
Commas separate numbers (e.g., 2,3-dimethyl).
Dashes separate numbers and letters (e.g., 2-methylpentane).
No spaces in the name.