Passage I

If a gum is added to water (such as the water in a food product ), the viscosity (resistance to flow) of the resulting aqueous mixture changes. Table 1 shows, for each of 4 gums (Gums W, X, Y, and Z), the viscosity, in centipoise (cP), of a 1.0% by mass aqueous mixture of the gum at 3 temperatures and at 3 resting times. A resting time is a period of time an aqueous mixture of a gum sits at rest just after having been prepared.

Figure 1 shows, for a certain temperature and a certain resting time, how the viscosity of aqueous mixtures of each of the 4 gums varies with gum concentration in percent by mass.

Table and figure adapted from G. O. Phillips and P. A. Williams, eds., Handbook of Hydrocolloids, 2nd ed. ©2009 by CRC Press and Woodhead Publishing, Ltd.

2. Based on Table 1, if a just-prepared 1.0% aqueous mixture of Gum Y is allowed to sit at rest for 100 min at 65°C, its viscosity will most likely be:

Answer and Explanation

Your Answer is

Correct Answer is H

Explanation

Summary of the data in table 1, it can be found that at the same temperature, the longer the resting time of a certain type of Gum, the greater the viscosity.

The 100 min given in the question stem is between 75-120 min, so according to table 1, the viscosity of Gum Y at 65°C and resting time of 100 min should also be between 802- Between 1075, the H option fits this range