At first define the chemical composition and aggregate state of substance. If gas is investigated, take its temperature, volume and pressure or place in normal conditions and measure only volume. After that calculate quantity of molecules and atoms. For determination of amount of atoms find their mass and molar mass, and then quantity of molecules and atoms in a solid body or liquid.
It is required to you
- the manometer, the thermometer, scales and Mendeleyev's table to recognize constant Avogadro.
Instruction
1. Determination of amount of atoms in gazes measure by the help of the manometer and thermometer pressure in Pascals and gas temperature in Kelvins. Then geometrically determine gas volume in the room or the vessel in cubic meters. After that multiply values of pressure and volume and divide into numerical value of temperature and number 8.31. Increase the received result by constant Avogadro who is equal 6.022*10^23. If temperature of gas is 273.15 Calvin (00C), and pressure of 760 mm Hg that is normal conditions, it is enough to measure the volume of gas in which the quantity of particles in cubic meters is defined, to divide it into number 0.224 and to increase on 6.022*10^23. At both ways if a gas molecule polyatomic, increase the received number by amount of atoms in molecules.
2. Determination of amount of atoms in a solid body or liquid from clean you veshchestvanaydit the mass of the studied body in grams. After that find the molecular mass of this pure substance which will be equal to its molar weight expressed in grams on mol in Mendeleyev's table. Then divide value of weight into molar weight and increase on 6.022*10^23.
3. Amount of atoms in substance with polyatomic to a molekulamiuznayta a chemical formula of substance. Then measure its weight in grams. By means of Mendeleyev's table learn the molar mass of each of elements which are included into structure of a molecule of the studied substance. For example, for table salt it is sodium and chlorine. If in a formula not one atom of one element, increase molar weight by their quantity. After that put all turned-out masses – receive the molar mass of this substance. Divide the mass of substance into its molar weight and increase on 6.022*10^23. Increase the received number by the total number of atoms in a molecule.
4. Determination of amount of atoms in mix of a veshchestvesla is mix, solution or fusion of several substances, learn their mass fractions in it. Then find the mass of these substances. For example, in 10% solution of table salt another 90% of water contain. Find the mass of solution then increase this weight by 0.1 to learn the mass of table salt and on 0.9 to learn the mass of water. After that act as in point for substances with polyatomic molecules, and put results on salt and water.