Below are a few general formulae. They are all assumed to have one functional group.

The restrictions on

As an example, the smallest ester would need TWO carbons, hence

**Alkane:**

C_{n}H_{2n+2} (n=1,2,3..)

**Cycloalkane:**

C_{n}H_{2n} (n=3,4,5...)

**Alkene:**

C_{n}H_{2n} (n=2,3,4...)

**Alkyne:**

C_{n}H_{2n-2} (n=2,,3,4...)

**Alcohol:**

C_{n}H_{2n+2}O or C_{n}H_{2n+1}OH (n=1,2,3...)

**Acid:**

C_{n}H_{2n}O_{2} (n=1,2,3...)

**Ester:**

C_{n}H_{2n}O_{2} (n=2,3,4...)

**Amine:**

C_{n}H_{2n+3}N (n=1,2,3...)

**Amide:**

C_{n}H_{2n+1}NO (n=1,2,3...)

**Aldehyde:**

C_{n}H_{2n}O (n=1,2,3...)

**Ketone:**

C_{n}H_{2n}O (n=3,4,5...)