Ascientist is trying to identify an unknown substance. the answer to which of the following questions would give the scientist information about a chemical property of the substance?
a. is it possible to change the shape of the substance?
b. does the substance corrode when left in water?
c. what color is the substance?
d. at what temperature does the substance melt?

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 .