you need
• - scales;
• - measuring cup;
• - table volumes.
Guide
1
Based on the definition, in order to know the density, you need to find the mass and volume of the body.This rule applies to solids and liquids.Put the body on the scale, and you will see desired quantity indicator.Put the resulting value in kilograms, which is the basic unit in the measurement system.If you learn a lot of liquid substance, before you pour it into the flask and weigh, find the mass of the flask.You will need to take it away from the result.
2
If the body whose density you want to find a regular geometric shape, your work will be much easier.To find the correct amount of shape, you can use the table of volumes, and find a formula to cal
culate the results of it.If the figure is wrong, take a measuring cup and fill it with water (not completely).Record at what is around the water.Then lower the test body in the water and check the number on which the water is now.The difference between the second and first value, and you will be necessary volume.The liquid volume can also be measured by the same measuring cup.
3
You just have to substitute the data into the formula ρ = m / V, where m - is the mass and V - volume of the substance.
4
gas density is different.To do this you need to know the molar mass of the gas and its normal volume.If, according to the condition of the problem, the action takes place, under normal conditions (temperature 0 degrees and 760 mm Hg), the normal volume is equal to 22.4 l / mole.Molar mass - is the mass of one mole of a substance.The formula for finding the density of gas is ρ = M / V standards.
5
If temperatures or pressures vary from the normal, is to determine the density of the gas you have to use the formula Clapeyron-Mendeleev and find the volume of gas: ρ * V = m / M * R * T, where ρ - ispressure, V - required volume, m - mass of gas M - molar mass, T - the temperature in Kelvin, and R - universal gas constant, which is equal to 8.3 J / mol * K.