Passage V
Students studied the photodecomposition (breakdown by light) of p-nitrophenol (a toxic pollutant) in wastewater. They measured the concentration of p-nitrophenol (in parts per million, ppm) in wastewater samples during exposure to various lighting conditions. Titanium dioxide (TiO2) and/or hydrogen peroxide (H2O2) were added to some samples at the start of exposure (time = 0 min). TiO2 and H2O2 speed up some photodecomposition reactions. The results of 3 sets of experiments are shown in Figures 1-3.
27. A chemist claimed that adding H2O2 to wastewater containing p-nitrophenol will cause the p-nitrophenol to decompose in the absence of light. Do the results from any of the figures confirm her claim?
Your Answer is
Correct Answer is D
Explanation
Looking at figure 3, all the curves in the figure have sunlight, so the test was not carried out under no-light conditions, and the decomposition under no-light conditions cannot be known