Is oil heavier than water

Answer 1

The short answer is, it depends on which oil you're talking about.

There are many different things that are considered "oils". For the most part, an oil is: hydrophobic (is repelled by water / doesn't mix with water), a liquid at 25°C, and is soluble in (mixes with) organic solvents.

How 'heavy' something is is determined by density. One way to describe the density of a liquid is by giving its 'specific gravity', which means how heavy is it compared to water. The specific gravity of water is 1, so any oil with a specific gravity greater than 1 will sink in water, while any oil with a specific gravity lower than 1 will float on water.

Most things that people are likely to encounter that they call 'oil', such as motor or vegetable oil, are lighter than water, but there certainly are oils that are heavier than water.

Answer 2

It depends on which oil you mean. Some oils are heavier than water, some are lighter. Most of things that the average person thinks of when they hear "oil", such as motor oil or vegetable oil, are lighter than water. Other oils are heavier. There are a huge number of things that are all considered 'oils', so the question needs to be more specific.