Most rooms have a regular geometric shape.They are parallel to the opposite walls.That is the volume of the space is calculated in the same way as the volume of a rectangular bar, for example.Measure the length (A), the width (B) and height (H) of the room, multiply these values ​​to yield a volume of: V = AhVhN.Make measurements convenient to construction tape.
Suppose you set such a task: how much take the air under normal conditions if the amount - 12 moles?Its solution is very simple.It is known that und
er normal conditions, the volume of one mole of any gas or gas mixture is about 22.4 liters.Multiply this value by 12, you get an answer: 22.4 * 12 = 268.8 liters.Or, about 0.27 m ^ 3.
slightly complicated task.For example, the number known to you air mass M is contained in a sealed vessel.This air acted external pressure value P at a temperature T. How much will take the air under such conditions?
Here you will famous equation Mendeleev-Clapeyron, derived independently by our compatriot DIMendeleev and French B.P.E.Klapeyronom.It describes the state of an ideal gas.Although air is, of course, it is not an ideal gas, this equation can be used if the calculation does not require high accuracy.Equation Mendeleev-Clapeyron written as: PV = MRT / m
values ​​P, M and T are known to you under the terms of the problem, the amount of R - universal gas constant can be found in any reference book on chemistry, physics, orInternet.It is equal to 8.31.The only remaining value of - m (molar mass of air ).It is precisely in the same manner and equal to 28.98 grams / mole.For convenience this round the value up to 29 g / mole.
little transforming the equation, you get the formula: V = MRT / mPPodstaviv known values ​​and calculations, get the required amount of air .