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.

29. Based on Figure 2, at 1 atm, which of the following solutions has a freezing point closest to the freezing point of pure H2O ?

Answer and Explanation

Your Answer is

Correct Answer is D

Explanation

The freezing point of H2O is 0°C, see figure 2, when the abscissa is 90%, the ordinate is 0, and the closest is 89% of option D