Consider the chemical equations shown here. 3 equations. First: 2 upper N upper O subscript 2 (g) right arrow 2 upper N upper o (g) plus upper O subscript 2 (g). Second: 2 upper N upper O (g) right arrow upper N subscript 2 (g) plus upper O subscript 2 (g). Third: upper N subscript 2 (g) plus 2 upper O subscript 2 (g) right arrow upper N subscript 2 upper O subscript 4 (g).