A student placed 3 grams of one reactant in a beaker and added 4 grams of another reactant A chemical reaction took place in the uncovered beaker When the student weighed the beaker after the reaction, she found the contents of the beaker weighed 5 grams Which of the following is the best possible explanation for her results?

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 .