To find the mass of one asking, define a chemical formula of substance, and by means of the periodic table of Mendeleyev calculate it. Weight of one asking calculate, having found the relation of mass of substance on its quantity. It is also possible to find the mass of one asking on the mass of one molecule of substance. For determination of mass of one of gas use Klapeyrona-Mendeleyev's equation.
It is required to you
- periodic table of Mendeleyev, scales, manometer and thermometer
Instruction
1. Determination of weight of one mole of a substance on a chemical formuleuznayta a chemical formula of a molecule of the studied substance. Then, find the atomic mass of each element entering a molecule according to the periodic table of Mendeleyev. If one element enters a formula several times, increase its atomic mass by the number of occurrences. Then summarize the turned-out mass numbers. The mass of a molecule in atomic units of mass which numerical is equal to molar weight this substances (that is the mass of one asking) in grams on mol will be result.
2. Determination of mass of one asking by the known amount of substance If the amount of substance in moths which molar mass needs to be found is known, by means of scales find its actual weight, having expressed it in grams. For determination of mass of one asking, the mass of substance divide M=m/υ into its quantity.
3. Determination of weight of one mole of a substance the mass of one molecule of substance expressed in grams is known for the mass of a molecule If find the mass of one asking, having increased the mass of this molecule by quantity of molecules in one pier (Avogadro's number) which is equal 6.022•10^23, M=m0 • NA.
4. Determination of mass of one of gas Take a tight vessel of the known volume expressed in cubic meters. Pump out from it gas, and weigh on scales. Pump in it gas, and again weigh, the difference of the empty and filled cylinders and will be equal to the mass of gas. Transfer it to kilograms. Take gas temperature in a cylinder if after downloading to wait a little, it will be equal to ambient temperature, and transfer it to kelvins, having added number 273 to degrees Celsius. Measure gas pressure by the manometer, in pascals. Find the molar mass of gas (the mass of one asking) having multiplied the mass of gas on its temperature and 8.31 (a universal gas constant), and having divided result into values of pressure and volume of M=m·R·T / (P•V).