He always says 'time is money' and strives not to waste a single second.

You should always be prepared for the time of need.

I woke up at the witching hour.

Following the customs of the time, they celebrated the festival.

During rush hour, the trains are very crowded.

Aspartic acid is one of the components of proteins.

Carboxylic acids play a very important role in organic chemistry.

Acetylsalicylic acid is commonly known as aspirin.

Barbituric acid is a type of organic acid compound.

In this chemical experiment, we will examine the properties of benzoic acid.