1. A car mechanic had a sealed bucket containing a substance in the gas phase. She left the bucket outside over the weekend. When she returned, the substance had changed phase, and the substance
was in the liquid phase. What happened to the molecules of this substance?

Nitric acid can be formed in two steps from the atmospheric gases nitrogen and oxygen, plus hydrogen prepared by reforming natural gas. in the first step, nitrogen and hydrogen react to form ammonia: (g) (g) (g) in the second step, ammonia and oxygen react to form nitric acid and water: (g) (g) (g) (g) calculate the net change in enthalpy for the formation of one mole of nitric acid from nitrogen, hydrogen and oxygen from these reactions. round your answer to the nearest .