Chemistry Quiz 8 Study Guide Terminology

What is organic chemistry?

The study of molecules composed primarily of carbon, but could also contain hydrogen, oxygen, nitrogen, sulfur, phosphorus, and/or halogens

• Includes:

  • naming organic molecules

  • properties of organic molecules

  • reactions of organic molecules

What are the organic molecules?

• Ethanol

• Tylenol

• Acetic Acid

• Vitamin C

• Amino Acids

• Testosterone

• Glucose

• Fatty Acid

• Acetone

• Carbon Dioxide

• Methane

What are the inorganic molecules?

• Sodium Chloride

• Silicon Dioxide

• Iron

• Potassium Hydroxide

• Hydrochloric Acid

• Nitrogen Gas

• Calcium

• Rust (iron oxide)

Why is carbon so special?

• Contains 4 valence electrons

  • Can make 4 bonds

• Small in size

  • Forms single/double/triple bonds

• Medium electronegativity

• Can make strong bonds with various other atoms

• Gets polar & non-polar molecules

What are hydrocarbons and their types?

Simplest organic compounds that only contain carbons and hydrogens.

• Types

  • Alkanes

  • Alkenes

  • Alkynes

What are alkanes?

• Contain only single bonds

• Saturated hydrocarbons: max number of single bonds

• Tetrahedral structure

• # of isomers increases as the # of carbons

• General Formula:

  • C_nH_2n+2 (open chains)

What are alkenes?

• Contain at least one C=C double bond

• General Formula:

  • C_nH_2n (for one double bond, acyclic)

What are alkynes?

• Contains at least one C≡C triple bond

• General Formula

  • C_nH_2n-2

What are isomers?

Compounds with same molecular formula but different structures.

• Structural isomers: occur due to branching in an alkane.

• Stereoisomers (later: geometric isomers for alkenes, enantiomers for chiral centers).

Rules for Naming Linear Chain Alkanes

1. Find the longest continuous carbon chain

2. Suffix is “-ane.”

3. Count Carbons to get Prefix

• 1 = meth-

• 2 = eth-

• 3 = prop-

• 4 = but-

• 5 = pent-

• 6 = hex-

• 7 = hept-

• 8 = oct-

• 9 = non-

• 10 = dec-

Rules for Naming Branched Alkanes

1. Find the longest continuous carbon chain

2. Branches (substituents) get suffix “-yl.”

3. Count Carbons to get Prefix

• 1 = meth-

• 2 = eth-

• 3 = prop-

• 4 = but-

• 5 = pent-

• 6 = hex-

• 7 = hept-

• 8 = oct-

• 9 = non-

• 10 = dec-

Rules for Naming Multiple Alkane Substituents

Linear Chain with Multiple Offshoots

1. Find the longest chain

2. Order substituents alphabetically

3. Use a prefix for repeating groups & give them the lowest #’s

• 2 = di-

• 3 = tri-

• 4 = tetra-

• 5 = penta-

• 6 = hexa-

Physical Properties

• Non-polar → insoluble in water.

• Density < 1 g/mL (float on water).

• Boiling & melting points increase as the # of carbons in the alkane increases

  • Greater surface area to make more dispersion forces (interactions).

• Branching lowers melting & boiling points as molecules cannot get as close together.

• Cycloalkanes: similar to acyclic of same carbons; small rings (cyclopropane) are strained.