ACT Science Practice Test 59

PASSAGE IV

Students wanted to test the effects of nutrition on the growth of guinea pigs. Two experiments were conducted using different feeds and vitamin supplements. For both experiments, four groups of 10 guinea pigs each were given a different type of feed over an 8-week period. Each group received the same quantity of food and was provided with fresh water daily. The guinea pigs were measured and weighed weekly. The guinea pigs in each group had an average starting weight of 50 grams (g) and an average starting length of 20 centimeters (cm).

Experiment 1

Group 1 was fed a high-protein feed (Feed P).

Group 2 was fed a grain-based feed with vitamin supplements (Feed Q).

Group 3 (control group) was fed a grain-based feed without supplements (Feed R).

Group 4 was fed a grain-based feed without supplements plus
fruits and vegetables (Feed S).

The results and average measurements are recorded in Table 1 below.

Experiment 2

Group 5 was fed a high-protein feed plus fruits and vegetables (Feed V).

Group 6 was fed a grain-based feed with vitamin supplements plus fruits and vegetables (Feed W).

Group 7 (control group) was fed a grain-based feed without supplements (Feed X).

Group 8 was fed a grain-based feed without supplements plus fruits only (Feed Y).

The results and average measurements are recorded in Table 2 below.

PASSAGE V

Students studied the effect of temperature on the conversion rates of two organic acids to their corresponding alcohols. The two organic acids studied were lactic acid (LA) and propionic acid (PA). Each acid was mixed with an Ru/C catalyst (to start the conversion) in an aqueous (water) solution. Lactic acid was found to break down into propylene glycol (PG), water, and various carbon side products. Propionic acid was found to break down into 1-propanol (1-PrOH), water, and various carbon side products. For all experiments, temperature was measured in degrees Kelvin (K).

Experiment 1

Students mixed an LA concentration of 0.5 moles (M) in a 50-milliliter (ml) aqueous solution along with a 5% Ru/C catalyst. The temperature was then varied to study the effect on the rate of conversion from lactic acid to PG. The results are shown in Figure 1.

Figure 1

Experiment 2

Students mixed a PA concentration of 0.5 M in a 50 ml aqueous solution along with a 5% Ru/C catalyst. The temperature was then varied to study the effect on the rate of conversion from propionic acid to 1-PrOH. The results are shown in Figure 2.

Figure 2