Passage II

Aluminum water-based paints (AWPs) contain aluminum (Al) flakes that give surfaces a shiny, metallic appearance. If the flakes corrode, a dull coating of aluminum hydroxide forms on them:

2Al + 6H2O → 2Al(OH)3 + 3H2

Table 1 shows the volume of H2 gas produced over time (at 25℃ and 1 atm) from 100 mL samples of freshly made AWPs 1-3 in 3 separate trials. AWPs 1-3 were identical except that each had a different concentration of DMEA, an AWP ingredient that increases pH.

The AWP 3 trial was repeated 4 times, but for each trial, the sample had the same concentration of 1 of 4 corrosion inhibitors (see Figure 1).

Figure 1 adapted from Bodo Muller. "Corrosion Inhibitors for Aluminum." ©1995 by Division of Chemical Education, Inc., American Chemical Society.

10. Consider the volume of H2 produced by Day 2 from the AWP 3 sample that contained no corrosion inhibitor. Based on Table 1 and Figure 1, the AWP 3 sample containing EDTA produced approximately the same volume of H2 by which of the following days?

Answer and Explanation

Your Answer is

Correct Answer is J

Explanation

Look at table 1 first, the volume of H2 produced by AWP3 on DAY 2 is 121;

Look at the EDTA curve in figure 1, the vertical coordinate is about 121, The abscissa is about DAY 10, so choose J