Difference between Acne and Boils. Key Difference: Acne is the disorder of the skin that is caused by oil and/or debris clogged pore. It is characterized by a presence of pimples, blackheads and whiteheads. A boil occurs due to an infected hair follicle. The infection is usually caused by the bacteria known as Staphylococcus.
By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water vapor, on average around 1% at sea level, and 0.4% over the entire atmosphere.
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.