A brown gas sample initially contains nitrogen dioxide, NO₂(g), which undergoes the reaction
2 NO₂(g) → 2 NO(g) + O₂(g)
The table below reports the measured concentration of NO₂ at three equally spaced times during the experiment. All concentrations are expressed in mol L⁻¹.
Time (s)
[NO₂] (M)
[O₂] (M)
0
0.080
0.000
60
0.068
———
120
0.056
———
Answer the following questions.
a. Calculate the concentration of O₂ at 60 s and at 120 s, completing the table above.
b. Describe the quantitative relationship between the rate of disappearance of NO₂ and the rate of appearance of O₂ for this reaction, and explain how that relationship guided your calculations in part (a).