Question 25 Answer and Explanation _ACT April 2010 Form 68G Science Section

Passage V

Ethylene oxide, a widely used industrial chemical, has the structure shown below:

Figures 1-3 each show how a property of solutions of ethylene oxide in H₂O varies as the concentration of ethylene oxide increases at 1 atmosphere (atm) of pressure. Concentration is given as the percent ethylene oxide by mass in H₂O (% EO). Figure 1 shows how density at 10°C varies with % EO. Figure 2 shows how freezing point varies with % EO. The bubble point is the lowest temperature at which bubbles of gas (in this case, ethylene oxide) form in a solution. Figure 3 shows how bubble point varies with% EO.

Figures adapted from Old World Industries, The Dow Chemical Company, Shell Chemical Company, Sunoco, Inc., and Equistar Chemicals, LP, Ethyleneoxide (2nd ed.). 1999.

25. According to Figure 3, the lowest temperature at which bubbles will form in a 30% EO solution at 1 atm is closest to which of the following?

A. 11°C

B. 25°C

C. 50°C

D. 97°C

Answer and Explanation

Your Answer is

Correct Answer is B

Explanation

Look at figure 3, when the abscissa is 30%, the corresponding ordinate is about 25°C