ORG CHEM | Drawing Organic Molecules

Molecular Formula

just shows atoms and number of each kind of atom

Structural Formulas

They show every element as its symbol and every bond as a line, similar to the Lewis Structure without the non-bonding electron pairs. It is best used for small and simple molecules to show the full connectivity.

Condensed Structural Formulas

The bonds to hydrogen atoms are not explicitly shown, making the formula more compact. The carbon atoms are grouped with the hydrogen atoms directly bonded to them.

Line-Bond/Skeletal Structures

Used in the professional field and for more complex structures, they represent the structure using lines, where the carbons are vertices or ends of lines. Bonds to other atoms except hydrogen are still shown.

Structural Isomers

They have the same molecular formula but multiple different connectivity of atoms.

n-Pentane

A straight-chain with a boiling point of 36 degrees.

Isopentane

A branched structure with a boiling point of 28 degrees.

Neopentane

Has a boiling point of 9.5 degrees

Carbon in Bonding

It is tetravalent. It can form four single bonds, two single binds and a double bond, and one single bond and a triple bond.

Hydrogen in Bonding

It is monovalent, meaning it can only form one bond.

Oxygen in Bonding (Neutral)

It has two bond and two lone pairs in compounds like water or alcohol.

Oxygen in Bonding (Negative Formal Charge)

It forms one bond and three lone pairs in compounds such as hydroxide ion.

Oxygen in Bonding (Positive Formal Charge)

It forms three bonds and one lone pair in compounds such as hydronium ion.

Nitrogen in Bonding

It trivalent. It typically forms three bonds and has one lone pair. It carries a positive formal charge with four bonds.

Halogens in Bonding

Fluorine (F), Chlorine (Cl), Bromine (Br), and Iodine (I) usually form one bond and have three lone pairs. They are usually seen in laboratory and medical contexts.

Sulfur in Bonding

It forms two bonds and behaves similarly to oxygen.

Phosphorus

They are usually in phosphate groups and can form five bonds since it can expand its valence shell.