* Diethyl ether (CH3CH2OCH2CH3): This is the most common ether, often called simply "ether." Its molecular mass is 74.12 g/mol.

* A general class of organic compounds: Ethers are a broad class of organic compounds with the general formula R-O-R', where R and R' are alkyl or aryl groups. To determine the molecular mass of a specific ether, you need to know the specific alkyl or aryl groups involved.

To calculate the molecular mass of any ether:

1. Identify the specific ether: Determine the exact chemical formula of the ether.

2. Determine the atomic masses of the elements: Look up the atomic masses of each element present in the ether from the periodic table.

3. Calculate the molecular mass: Multiply the atomic mass of each element by the number of atoms of that element in the molecule and add the results together.

Example:

Let's calculate the molecular mass of methyl ethyl ether (CH3OCH2CH3):

* Carbon (C): 12.01 g/mol x 3 = 36.03 g/mol

* Hydrogen (H): 1.01 g/mol x 6 = 6.06 g/mol

* Oxygen (O): 16.00 g/mol x 1 = 16.00 g/mol

Total molecular mass = 36.03 + 6.06 + 16.00 = 58.09 g/mol