I can draw three characteristics from the properties of gases. Compressibility, expandability, and the way gases take up more space than liquids or solids in their current form. An extraordinary example of this characteristic with which we describe the compressibility of gases is the way a Porsche 911 sports car works. A sports 911 Porsche runs on an internal combustion engine (usually v8/ but in this case I'm talking about a particular four-stroke ), in which it “compresses the gases” just as I said before. To work, the engine piston moves out of the cylinder to create a vacuum that draws a mixture of oxygen and gasoline vapor into the engine cylinder compartment. Then, a few seconds later, the piston rotates, pushing back into the cylinder, compressing the fuel/air mixture to a new volume, compared to the volume it had when the piston was rotated at the top of its seat. The typical car has a compressibility ratio of 9 to 1, but this Porsche has a compressibility of about 7 to 1, which may mean that the gas-air mixture in the cylinder is compressed by a factor of 7. The second property I would like outline on gases is expandability. Anyone who has entered a bathroom where many people have just taken a number 2, has experienced in his face that gases expand to fill the container, while the air in the disgusting bathroom is filled with terrible waste smells. Just like people smell during a Formula 1 race, the distinctive odor of C2H5OH ethanol quickly spreads across the track as it makes its way between the cars and even onto the pit stop track. Gases expand to fill their containers, so it's safe to say that the volume of a specific gas can be equal to its volume... half the paper... everything is represented in moles, so ideal the gas law must be used to resolve the volume or mass of the bass involved in the reaction. For example, if you wanted to calculate the volume of NO2 produced by the combustion of 100 g of NH3, through the reaction 4NH3 +7O2=4NO2 + 6H2O. It could be solved by multiplying 100 g of NH3 by 1 mol of NH3/17.034gNH3= 5.871 mol of NH3. But on the other hand the chemical reaction is given in terms of moles, not grams, so you need to use the ideal gas law to solve for the volume or mass of the gas involved in the reaction. Using the same example as before, if I wanted to continue the process: There is a 1 to 1 molar ratio of NH3 to NO2 in the balanced combustion reaction, so 5.871 mol of NO2 will be formed. Using PV=nRT to solve for volume at zero degrees (273.15 K) and 1 atm using the gas law constant R=008206 times atm times K-1 times mol -1.