To find water density, it is necessary to determine its weight and volume. Massú is found by means of scales, and volume geometrical methods in a form of a vessel or by means of a special measured cylinder, having determined previously the price of its division. Other way of determination of density of water is made by means of the device which is called the areometer.
It is required to you
- scales, and areometer.
Instruction
1. It is known that pure density is 1 g/cm³ or 1000 kg/cm³. But various impurity which can contain in this best natural solvent can change this size considerably. For example, sea water has a little big density, than clean. To find water density, measure its weight. For this purpose select a sample of water which density is defined. At first weigh an empty vessel in which measurement will be performed, then fill it with water and again weigh. The difference of mass of the filled with water and empty vessel will be equal to a water mass. It is better to perform measurement in grams.
2. Find water volume. For this purpose you will calculate it geometrically if water is filled in in a vessel of the correct form. In case the vessel has the parallelepiped form, increase its length by width and depth of liquid measured in centimeters. If a vessel of a cylindrical form, measure its diameter, and calculate the area of the basis, having increased diameter square by 3.14 and having divided into 4. Increase the area of the basis of a cylinder by liquid column height, water volume in a vessel will be result. In case the measured cylinder is available, pour the selected test water into it and on a scale, previously having determined the division price, find liquid volume. Measure this size in ml or cm³ which are equivalent among themselves.
3. Divide the lot of the selected test of water measured on scales into the received volume ρ=m/V. At such measurement of sizes, density measured in grams on cubic centimeter will turn out. To receive this size in kilograms per cubic meter, increase the received value for 1000.
4. To measure liquid density by the areometer, ship it in a vessel with water so that it did not shake its walls and a bottom, freely floating on a surface. On its top part determine water density by a scale. If it is known what substance in it is dissolved, changing scales, by means of the areometer, find its concentration.