**IUPAC Name of CH3OCHO: Methoxyethanal**

The IUPAC name of CH3OCHO is Methoxyethanal. Let's break down the name to understand it in detail.

**1. Identify the Longest Carbon Chain**
The molecule CH3OCHO contains two carbon atoms. We need to identify the longest carbon chain in the molecule to determine the base name. In this case, the longest carbon chain consists of two carbon atoms.

**2. Identify the Functional Group**
The functional group in CH3OCHO is an aldehyde group (CHO), which is attached to one of the carbon atoms in the longest chain.

**3. Number the Carbon Atoms**
Next, we need to number the carbon atoms in the longest chain. Since there are only two carbon atoms, we start numbering from the carbon attached to the aldehyde group.

**4. Assign Locants**
The aldehyde group is attached to the first carbon atom, so it is assigned the locant "1". The other carbon atom is then assigned the locant "2".

**5. Name the Aldehyde Group**
The aldehyde group is named as "oxo" in IUPAC nomenclature. Therefore, we can use the term "oxo" to describe the functional group.

**6. Name the Alkyl Group**
The alkyl group attached to the second carbon atom is a methyl group (CH3). It is named as "meth-" in IUPAC nomenclature.

**7. Combine the Names**
Now, we can combine the names of the functional group and the alkyl group. The aldehyde group is named as "oxo" and the methyl group is named as "meth-". Therefore, the IUPAC name becomes "methoxo".

**8. Add the Suffix**
Finally, we add the suffix "-al" to indicate that the compound is an aldehyde. So, the IUPAC name of CH3OCHO is "methoxo + al = Methoxyethanal".

In summary, the IUPAC name of CH3OCHO is Methoxyethanal. The "meth-" prefix represents the methyl group, "oxo" represents the aldehyde group, and "-al" is the suffix indicating an aldehyde compound.