Instruction

1

Suppose you know the number of moles of oxygen (e.g. 5). You face the question: how much under normal conditions takes these 5 moles? The solution is: under normal conditions the volume of 1 mole of any gas is constant and is approximately equal to 22.4 liters. Therefore, 5 moles of oxygen at normal conditions will occupy a volume of 22.4*5 = 112 liters.

2

Well, if you know the mass of oxygen? Suppose 96 grams. What is the amount they take under normal conditions? First, find out how many moles of oxygen contains 96 grams of this substance. Molar mass of oxygen (from the formula O2) = 32 grams/mol. Therefore, 96 grams of 3 moles. Performing the multiplication, we get the following response: 22,4*3 = 67.2 per liter.

3

But if you need to determine the amount of oxygen at conditions other than normal? Then you come to the aid of the universal equation Mendeleev-Clapeyron describing the state of the so-called "ideal gas". It is written like this:

PV = RTM/m, where p is the gas pressure in Pascals, V is the volume in liters, R is the universal gas constant, T is the gas temperature in degrees Kelvin, M is the mass of gas, m is its molar mass.

PV = RTM/m, where p is the gas pressure in Pascals, V is the volume in liters, R is the universal gas constant, T is the gas temperature in degrees Kelvin, M is the mass of gas, m is its molar mass.

4

Transforming the equation, we get:

V = RTM/mP.

V = RTM/mP.

5

As you can see, if you have the necessary for calculation data (temperature, mass, and oxygen pressure), calculate its volume very simple. Because the values of R (8,31) and m (32) you know.

Useful advice

Of course, the oxygen (or any other gas) cannot be considered an ideal gas, so the equation Mendeleev-Clapeyron, strictly speaking, not quite accurately describes his condition. However, if the pressure and temperature of the gas is not very different from normal, it can be used in the calculations. The error will be negligible.

# Advice 2: How to calculate the volume

The volume is the space occupied by the body. To calculate the correct volume of the object, which can easily determine the parameters (length, width, height) easy. It is only necessary to multiply the found value. To determine the volume of arbitrary shapes is much more difficult.

Instruction

1

A method of measuring the volume of the object with water was open to the Greek scientist Archimedes. To determine the volume of any body need to take a container of liquid, it is better if the container is transparent. The vessel must be applied to the scale division and to measure the volume occupied by water. After that, the water should immerse the body whose volume you want to learn. As soon as the water rises, you must mark the new level. The difference in levels, obtained by measurement and is equal to the volume of the immersed body.

2

In addition, it is possible to determine the volume of the object by measuring the amount of water displaced by it. For this purpose, in a vessel brim full of water, it is necessary to load the body. With the displaced water should be poured into another container and measure the volume, which will be equal to the desired volume of the body.

3

When finding the volume of a hollow body you can also use the water. For this you need to fill it are available, subject, and then pour the water into a glass, which is applied to the scale division. The measured body volume is equal to the volume of contained water in it.

4

You can calculate the volume of any body, knowing its density and mass. It is necessary to divide the available mass of the object on its density. To know the density of the material from which made a particular item from the reference table "Density of solids".

5

To calculate some of the figures are derived mathematical formulas. For example, for finding the volume of a cylinder we need to know its radius and height. The volume of a cylinder you will receive by works of "PI" to the square of the radius and height of the body (V=π*R2*H).