Chloroethane (other names – chloride ethyl, ethyl chloride) represents itself colourless gas, has a chemical formula C2H5Cl. Mixes up with ethyl alcohol and ethyl oxide, almost does not mix up with water. How it is possible to receive this substance?

To calculate amount of substance, learn its weight by means of scales, express it in grams and divide into the molar weight which can be found by means of Mendeleyev's table. In normal conditions apply Avogadro's law to determination of amount of substance of gas. If gas is in other conditions, measure pressure, volume and temperature of gas then calculate amount of substance in it.

Ethane and propane – gases, the most ordinary representatives of a number of saturated hydrocarbons - alkanes. Their chemical formulas C2H6 and C3H8 respectively. Ethane serves as raw materials for production of ethylene. Propane is used as fuel as in pure form, and in mix with other hydrocarbons.

The molecule is electrically the neutral particle having all chemical properties inherent in this concrete substance. Including to gases: to oxygen, nitrogen, chlorine, etc. How it is possible to define quantity of molecules of gas?