Which statement correctly describes a sample of gas confined in a sealed container? (1) it always has a definite volume, and it takes the shape of the container. (2) it takes the shape and the volume of any container in which it is confined. (3) it has a crystalline structure. (4) it consists of particles arranged in a regular geometric pattern.

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 .