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.

26. At 10°C and 1 atm, as % EO increases from 0% to 100%, the mass per unit volume:

Answer and Explanation

Your Answer is

Correct Answer is G

Explanation

Look at figure 1. The question is about volume. There is no chart related to volume, so find the density directly related to volume.

The abscissa is from 0%-100%, and the ordinate is decreasing, indicating that the density is decreasing. m=ρV, under the same volume, the smaller the density, the smaller the mass m should be