No, not all liquids contain water. While water is a common solvent and one of the most prevalent liquids on Earth, there are many other types of liquids that do not include water in their composition.
For instance, oils (like olive oil or motor oil) and alcohols (like ethanol or isopropyl alcohol) are both classified as liquids, but they do not contain water. Additionally, liquids such as mercury and various other chemical solutions are also free of water.
The term ‘liquid’ refers to the physical state of a substance that flows freely and has a definite volume, but it doesn’t imply that water must be present. Each liquid has its unique characteristics and chemical composition, which determines its properties and behavior. So, while water is an essential and fundamental liquid for life, not all liquids include it.