# Question #ddef4

##### 1 Answer

#### Answer:

**Deviation from ideal behaviour** means the difference between the ideal value and the experimental value of a property.

#### Explanation:

At ordinary temperatures, real gases behave **almost** like ideal gases.

For example, the volume of 1.00 mol of an ideal gas at 1 bar and 0 °C. is 22.7 L.

The volume of 1 mol of

At low temperatures and high pressures, the differences become much larger.

For example, let's calculate the volume of 1.00 mol of carbon dioxide as an ideal gas at **150 bar and 200 K**.

The actual volume under these conditions is 51 mL.

The actual volume is **less than half** of the ideal volume, because of the attractive forces of the molecules for each other

Now, let's repeat the calculation at a pressure of **900 bar and 200 K**..

The actual volume under these conditions is 48 mL.

The actual volume is **2.5 times greater** than the ideal volume, because at this high pressure the volumes of the molecules themselves are a large proportion of the space.