How to calculate the volume of air

Air is a mixture of many gases. The most massive component is nitrogen, the second most essential for any living organism element – oxygen. Third place by the percentage of the inert gas is argon, the fourth carbon. The concentrations of all other gases: hydrogen, methane, and other inert gases, etc., so little that in most cases they can be neglected in the calculations. Is it possible to calculate the volume of airlocated in the premises or in any vessel? Of course, you can.

Instruction

1. Most areas have regular geometric shapes. Their opposite walls are parallel. That is, the volume of such space calculated exactly the same as the volume of a rectangular bar, for example. Measure the length (A) width (b) and height (H) of the room, multiply those values, the result is the volume: V = Ahvhn. To measure the preferred construction roulette.
2. Suppose you are given this task: how much is the air under normal conditions, if the number – 12 of moles? Its solution is very simple. As you know, under normal conditions the volume of one mole of any gas or mixture of gases is approximately 22.4 liters. Multiply this value by 12, we get the answer: 22,4* 12 = 268,8 liters. Or, about 0.27 m^3.
3. A little complicate the task. For example, a known quantity of air of mass M enclosed in a sealed vessel. This air is acted by external pressure P, temperature T. What volume will the air occupy under these conditions?
4. Then you will be famous equation Mendeleev-Clapeyron derived independently from each other our compatriot Mendeleev and the French B. P. E. Clapeyron. It describes the state of an ideal gas. Although the air, of course, is not an ideal gas, this equation can be used if the calculations do not require high accuracy. The equation Mendeleev-Clapeyron written as:PV = MRT/m
5. Values R, M, T you are aware of the conditions of the problem, the value of R is the universal gas constant can be found in any reference book on chemistry, physics, or the web. It is equal to 8,31. The only remaining size – m (molar mass of air). It is in exactly the same way, and equal of 28.98 g/mol. For convenience of calculations, we round this value up to 29 g/mol.
6. Slightly transforming equation you get the formula:V = MRT/bodstein the known values and performing the calculation, locate the desired volume of air.