ACT science practice test 58

Directions: Each passage is followed by several questions. After reading a passage, choose the best answer to each question and fill in the corresponding oval on your answer document. You may refer to the passages as often as necessary.

You are NOT permitted to use a calculator on this test.

In the early 1800s, chemists started experimenting with different chemicals. They had the ability to measure the temperature, pressure, and mass of a sample of gas. In 1911, a chemist named Amadeo Avogadro published an observation that came to be known as Avogadro's law. This law states that any two gasses that are held under the same pressure, temperature, and volume will contain the same number of molecules (measured in moles) regardless of the identity of the gasses. Table 11.1 shows data collected from various gas samples at 1 atm and 0°C.

TABLE 11.1

1. According to Table 11.1, which sample of gas took up the most space?

A. Sample 1
B. Sample 4
C. Sample 6
D. Sample 7

2. Comparing Samples 1 and 3, one can state that:

A. Samples 1 and 3 are the same size and the same mass.
B. Sample 1 is larger, but Sample 3 is more massive.
C. Sample 3 is larger, but Sample 1 is more massive.
D. Samples 1 and 3 are the same size, but Sample 3 is more massive.

3. Referring to Table 11.1, how does the number of gas molecules in Sample 4 compare to the number of gas molecules in Sample 5?

A. Sample 4 has more molecules.
B. Sample 5 has more molecules.
C. Samples 4 and 5 have the same number of molecules.
D. It is impossible to determine from the data given.

4. How much mass would a 22.4-L sample of oxygen gas have when measured at 1 atm and 0°C?

A. 4.0 g
B. 20.2 g
C. 32.0 g
D. 44.8 g

5. In the early 1800s, mass was measured with a double-pan balance. If a 11.2-L sample of neon is placed in one side of the balance, what volume of hydrogen would have to be placed on the other side to have an equal amount of mass?

A. 224.0 L
B. 112.0 L
C. 22.4 L
D. 11.2 L

6. Referring to Avogadro's law and Table 11.1, which of the following places the samples of gas in order from the least number of molecules to the most?

A. Sample 1, Sample 3, Sample 7
B. Sample 7, Sample 3, Sample 1
C. Samples 3 and 1 have an equal number of molecules, but Sample 7 has more.
D. All the samples have an equal number of molecules.

7. What can be said about the mass of one molecule of helium and one molecule of oxygen gas?

A. One molecule of helium has the same mass as one molecule of hydrogen gas.
B. One molecule of oxygen is 8 times more massive than one molecule of helium.
C. One molecule of helium is 8 times more massive than one molecule of oxygen gas.
D. One molecule of oxygen gas is 4 times more massive than one molecule of helium.

8. Chemists counted molecules in the unit of moles. Avogadro stated that 1 mole (mol) of gas particles at 1 atm and 0°C takes up a volume of 22.4 L. What is the mass of 1 mol of oxygen gas molecules?

A. 32.0 g
B. 16.0 g
C. 8.0 g
D. 4.0 g