How can the experimental mass be easily calculated

2.1.2 Density of gases

Determination of the density of the air. Flask is first weighed with air, then evacuated and weighed again.

The density of gases can be determined experimentally by taking mass m and volume V measures.

The density of the air can be determined, for example, by weighing a flask with air and then evacuating it. With a volume of 4 l, for example, the difference measurement gives a mass of air of

This gives for the density

The density of gases is temperature dependent and pressure dependentas can also be seen from the law of Avogadro:

Here designated m the mass of the gas and M. the relative molecular mass.

With the density you get or.

Under isothermal conditions (T= const) the pressure is proportional to the density.

 

 

© University of Würzburg, Tilo Hemmert 2000