Most commonly known as soda ash, sodium carbonate is used in many cleaning agents and in glass making. Most soda ash is mined from trona ore, but it can be manufactured by reacting salt and sulfuric acid. Perhaps the most widely used industrial insulation. This is the chemical that is made from cyclohexane and in turn is polymerized to nylon. Due to its toxic affect on mammals, the EPA has been ordering a decrease in it's use and an increase in the use of ethanol as a replacement.
Most common application is it's reaction with ammonia to form the solid fertilizer ammonium nitrate.
Also a very common organic solvent as well as a precursor to cyclohexane. The majority of urea is used in fertilizer production. Some is also used in the manufacture of livestock feed. Polystyrene is used in pure form and expanded. Typically produced from synthesis gases, namely carbon monoxide and hydrogen.