It is the second-smallest county by total area in Maryland. Notable waterways include the Choptank River and Tuckahoe Creek, as well as the man-made Williston Lake. Caroline County currently ranks seventh nationally in terms of land protected under the Ag Preservation Program.
Dry air contains roughly (by volume): All the above are relatively small, light, non-polar molecules, characteristics mimicking an ideal gas. At normal ambient conditions such as standard temperature and pressure, most real gases behave qualitatively like an ideal gas.
Atmospheric Air contains approximately 21% oxygen (O2) by volume. The other 79% of other gases is mostly nitrogen (N2), so we will assume air to be composed of 21% oxygen and 79% nitrogen by volume. Thus each mole of oxygen needed to oxidize the hydrocarbon is accompanied by 79/21 = 3.76 moles of nitrogen. Using this combination the molecular mass of air becomes 29 [kg/kmol]. Note that it is assumed that the nitrogen will not normally undergo any chemical reaction.