Question 18 Answer and Explanation _ACT June 2019 Form B02 Science Section

Passage III

Students performed 3 experiments to investigate the absorption of H₂O by dried chickpeas (a type of bean).

Experiment 1

A sample of 50 dried chickpeas with similar sizes and masse was selected. The total mass of the sample was measured, and the average initial mass per chickpea (CM_i) was calculated. The sample was immersed in 200 mL of distilled H₂O at 20°C. After 20 min, 5 chickpeas were removed from the distilled H₂O and gently patted dry with a paper towel, and their total mass was then measured. The average final mass per chickpea (CM_f) was calculated. At each of 6 different time thereafter, another 5 chickpeas were removed from the distilled H₂O and gently patted dry with a paper towel, and their CM_f was determined. The average moisture uptake per chickpea (CMU) was then calculated for each group of 5 chickpeas using the following equation:

The results are shown in Table 1.

Experiment 2

The students repeated the procedure from Experiment 1 at 4 other temperatures (see Table 2).

Experiment 3

The students repeated the procedure from Experiment 1, except that they replaced the distilled H₂O with aqueous solutions of NaCl at 3 different concentrations (see Table 3).

18. Consider the results of Experiments 1 and 3. At any given soaking time, compared with the CMU of the chickpeas soaked in distilled H₂O, the CMU of the chickpeas soaked in an NaCl solution was:

F. always greater.

G. always less.

H. always the same.

J. sometimes greater and sometimes less, depending on the NaCl concentration.

Answer and Explanation

Your Answer is

Correct Answer is G

Explanation

Comparing the CMU at 20 minutes in table 1 and 20 minutes in table 3, it is found that the data in table 3 is smaller, indicating that the NaCl solution will reduce the CMU