The rate at which a liquid expands when heated is called its coefficient of thermal expansion. The coefficient of thermal expansion is a measure of how much the liquid's volume will change for a given temperature increase.
The coefficient of thermal expansion for water is 0.00021 °C^-1. This means that for every 1 °C increase in temperature, the volume of water will increase by 0.00021 times its original volume.
Some liquids, such as mercury, actually decrease in volume when they are heated. This is because the arrangement of the molecules in these liquids is such that they become more densely packed when they are heated.
The coefficient of thermal expansion for a liquid can be used to calculate how much the volume of the liquid will change when it is heated or cooled. The following formula can be used:
```
ΔV = V * α * ΔT
```
where:
- ΔV is the change in volume of the liquid
- V is the original volume of the liquid
- α is the coefficient of thermal expansion for the liquid
- ΔT is the change in temperature
For example, if you have a liter of water at room temperature (25 °C) and you heat it to 100 °C, its volume will increase by:
```
ΔV = 1000 mL * 0.00021 °C^-1 * (100 °C - 25 °C)
ΔV = 1.575 mL
```
Therefore, the volume of the water will increase by 1.575 mL when it is heated from 25 °C to 100 °C.
