Density of Air and Carbon Dioxide

Problem Students are surely aware of the atmosphere of air which surrounds us and our earth. To a much lesser degree, they identify air as a space-filling substance or as a mixture of substances with a characteristic and measurable density. This density should be established and compared with other gases. The density of air and its connection to sea level measurements can also be discussed in connection with the decrease of air pressure by climbing high mountains. 

Material Analytical balance, round flask with stopcock, syringe, vacuum source (water aspirator or vacuum pump), test tube carbon dioxide (lecture bottle). 

Observation 100ml air weighs 0.13g. 100ml carbon dioxide weighs 0.2g. The densities can be calculated to 1.3 g/1 (literature value 1.29 g/1) and to 2.0 g/1 (literature value 1.97 g/1). 

Tip This experiment can also be carried out using a plastic bottle with stopper and stopcock one weighs the bottle filled with air and attached stop cock, presses 100 ml of gas into the plastic bottle and weighs again. 

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