Test Format
True or False
Polio Passage
Osmotic Pressure
100

How many questions are on ACT Science?

40

100

True/False: Read the whole passage in full and try to absorb as much information as possible.

False. Use locators to determine the answer.

100

According to Figure 1, the greatest increase in the number of reported polio infections in Nigeria occurred between which two months?

A. January and February
B. February and March
C. April and May
D. November and December

Correct Answer: B

There are large increases in the number of reported cases from January to February and from February to March, but upon close inspection, the transition from February to March is larger. Therefore, choice (B) is the best answer.

100

According to Figure 1, which of the following solutions would exhibit the least osmotic pressure?

A. 1.0 M FeCl3 solution
B. 1.0 M MgCl2 solution
C. 2.0 M NaCl solution
D. 2.0 M sucrose solution

D is the best answer.

The solution with the least osmotic pressure will have the smallest value from Figure 1. The pressure for choice (A) is 85 atm; choice (B) is 70 atm; choice (C) is 90 atm; choice (D) is 50 atm. Therefore, a 2.0 M sucrose solution has the least osmotic pressure.

200

How much time do you have to complete ACT Science?

35 minutes

200

You will probably need a calculator to answer some of the questions in ACT Science (even though you won't have access to one)

False. Any information you need is on the page or in the passage. Use simple math (round, estimate, and approximate).

200

It is estimated that for every person infected with the polio virus in an endemic country, there are 200 people at risk for contracting the virus. Given the results of Study 1, how many people would have been at risk for becoming infected with the polio virus in Nigeria in June 2004?

Correct Answer: J

In June 2004, 80 cases of polio infection were reported, so 80 × 200 = 16,000 people would have been at risk for contraction of the infection.

200

If 1.0 M solutions of various solutes were prepared, which of the following solutions would have the highest level of ionization?

F. Sucrose
G. NaCl
H. MgCl2
J. FeCl3

J is the best answer.

J The introduction states that higher van't Hoff factors correlate with greater dissociation or ionization. According to Table 1, FeCl3 exhibits the greatest van't Hoff factor, which means the highest degree of ionization.

300

ACT Science is made up of how many passages? (range)

6-7 passages

300

True/False: You do not need to know much Science knowledge to do well on this test. 90-95 percent of the questions are not based on content knowledge.

True! only 5-10 percent of ACT Science questions require you to know science knowledge that isn't written on the page. (For example, you may need to know what volume is, or the periodic symbol for iron.)

300

Polio-endemic countries are located in warm climates that harbor many mosquitoes. Would the presence of mosquitoes directly affect the transmission of the polio virus?

A. Yes, because the polio virus is primarily transmitted through mosquitoes.
B. Yes, because the polio virus is primarily transmitted through human waste.
C. No, because the polio virus is primarily transmitted through mosquitoes.
D. No, because the polio virus is primarily transmitted through human waste.

Correct Answer: D

The passage states that the polio virus is most often transmitted through water contaminated with human waste and makes no mention of the role (or the lack thereof) that other life forms play in the transmission of the virus. The answer that summarizes this is choice (D).

300

Based on Figure 1, as the concentration of solute decreases, the pressure required to hold solvent concentration across a membrane at equilibrium will:

F. increase only.
G. decrease only.
H. remain constant.
J. increase, then remain constant.

G is the best answer.

he pressure required to maintain solvent equilibrium across a membrane is the solution's osmotic pressure, as discussed in the introduction. Figure 1 shows a linear relationship between solute concentration and osmotic, eliminating choices (H) and (J). As concentration of solute decreases, the osmotic pressure will also decrease, eliminating choice (F).

400

Name 3 of the 4 categories of Science tested on the ACT.

Biology, Chemistry, Physics, Earth/Space Science

400

True/False: If you're having a difficult time getting to all of the passages, you may consider skipping 1 or 2 of them all together.

True. Skipping one or two passages could give you a little extra time to spend on the other passages. Don't forget to still make guesses on skipped questions!

400

Given the information in Figure 2, which of the following might explain the difference in reported cases of polio in major Indian cities between June and August of 2007?

A. Water is more likely to become contaminated with polio-infected human waste in periods of high rainfall.
B. Water is less likely to become contaminated with polio-infected human waste in periods of high rainfall.
C. The polio virus infects more people in India during the summer and monsoon seasons than during the autumn and winter seasons.
D. Those diagnosed with the polio virus in June are able to recover by August.

Correct Answer: A

Choice (A) is the best answer because the month of August is expected to have more rainfall, and therefore is more likely to feature water contamination.

400

A scientist recently discovered a compound that ionizes readily in solution (i = 3.8) and results in low osmotic pressures. Are the findings of this scientist consistent with Figure 1?

A. Yes, because FeCl3 causes higher osmotic pressure than sucrose.
B. No, because sucrose causes higher osmotic pressure than FeCl3.
C. Yes, because FeCl3 causes lower osmotic pressure than sucrose.
D. No, because sucrose causes lower osmotic pressure than FeCl3.

D is the best answer.

Comparing different solutes in Figure 1 at a given concentration greater than M = 0, you will determine that FeCl3 always has greater osmotic pressure than sucrose, eliminating choices (B) and (C). The trend in Figure 1 predicts that a substance with i = 3.8 would have a greater osmotic pressure than FeCl3, which does not support the scientist's findings.

500

Which question type shows up the MOST on the Science ACT? 

A. Data Representation

B. Research Summaries 

C. Conflicting Viewpoints

Research Summary questions make up 45%-55% of ACT Science test. (about 18-22 questions)

500

True/False: You should find the Conflicting Viewpoints passage FIRST and complete it at the very beginning of the testing time.

False! Conflicting Viewpoints passages and questions are more difficult and can be time consuming. You should skip the Conflicting Viewpoints passage and save it for last so that you have enough time to answer the easier questions.

500

The comparison of reported polio infections in India in 2007, as shown in Figure 2, indicates that relative to the number of people in Kolkata infected with polio in June, the number of people infected with polio in Kolkata in August was approximately:

F. half as much.
G. the same.
H. twice as much.
J. ten times as much

H is the best answer.

In June 2007, there were between 10 and 15 reported polio infections in Kolkata, while in August 2007, there were between 20 and 25 reported polio infections. This is an approximate doubling of the number of reported infections, so choice (H) is the best answer.

500

Which of the following solutions would exhibit the closest osmotic pressure to that of a 1.5 M NaCl solution at 300 K, if the gas constant is 0.0821 L atm/ mol-1 K-1?

A. 1.0 M NaCl solution (i = 1.9)
B. 2.0 M NaCl solution (i = 1.9)
C. 2.9 M Sucrose solution (i = 1.0)
D. 3.5 M Sucrose solution (i = 1.0)

C is the best answer.

M
e
n
u