write an equation for a reaction involving an aldehyde to illustrate a hydrogenation reaction.
Hydrogenation of an aldehyde produces an alcohol. Here is a good discussion.
http://chemed.chem.purdue.edu/genchem/topicreview/bp/2organic/aldehyde.html
To write an equation for a hydrogenation reaction involving an aldehyde, you need to understand the process of hydrogenation and the chemical formula of the aldehyde involved.
Hydrogenation is a reaction where hydrogen atoms are added to a double or triple bond. In the case of aldehydes, they contain a carbonyl group, which is a double bond between carbon and oxygen. During hydrogenation, this double bond is converted into a single bond, and hydrogen atoms are added to the carbon atom.
The general equation for hydrogenation reactions is:
Alkene/Alkyne + H2 → Alkane
To apply this equation to an aldehyde, you need to convert the carbonyl group into either an alkene or an alkyne. To do this, replace the oxygen atom with a carbon atom, and attach the remaining parts according to the valencies.
For example, let's consider the aldehyde formaldehyde (HCHO). By replacing the oxygen in the carbonyl group with a carbon atom and adding hydrogen atoms, we can convert it to an alkane:
HCHO + H2 → CH3CH2OH
In this example, formaldehyde reacts with hydrogen gas (H2) to form ethyl alcohol (CH3CH2OH) through a hydrogenation reaction. Note that the aldehyde is converted into an alcohol (an alkane with a hydroxyl group).
Keep in mind that this is just an example, and the specific aldehyde used in a hydrogenation reaction may vary, resulting in different products.