Figure 1. According to the passage, all readings are taken at atmospheric pressure 101.3 kPa,
so you can disregard that part of the question. The melting point of the solution seems to be
lowest around 70% EG. The closest of the answers is (B), 68%.
2 . H Use Figure 1. According to the passage, all readings are taking at atmospheric pressure 101.3
kPa, so you can disregard that part of the question. According to Figure 1, at 60% EG, the
melting point is roughly −48°C, as in (H).
3 . A The substance that will behave most like pure water and boil at the same temperature would
be pure water itself. Choice (A), 0% EG, would mean a solution of no ethylene glycol and
all water. Increasing the % EG, as in (B), (C), and (D), and therefore decreasing the
percentage of water, would make the solution behave less like water.
4 . F This question requires a bit of outside knowledge: “density” and “mass per unit length” are
one in the same. Therefore, you can use Figure 3 to answer this question even though the
word “density” does not appear explicitly in this question. According to the passage, all
density readings are taken at a temperature of 25°C, so you can disregard that temperature
and just look at the graph. According to this graph, as % EG increases, the density steadily
increases as well. The best answer, therefore, comes from (F).
5 . B According to Figure 2, a substance with a density of 1.09 g/mL has 40% EG. Use this EG
value on Figure 3. According to Figure 3, a substance with 40% EG has a boiling point of
approximately 104°C. Only (B) works.
Passage VIII
1 . D The axes given in Figure 3 are “crystal mass (g)” and “crystal volume (cm^3 ).” According to
the key, different levels of radiation were measured. Nowhere in any of these axes or curves
do we have any indication of the number of crystals measured. Without this information, and
without any relevant information in the introduction, we can’t determine how many crystals
were measured, making (D) the only possible answer.
2 . G Although this question does not mention one specific figure, look at the variables to be
compared. We’ll need to make a prediction about volume based on radiation level. The only
one of the three figures that compares these two variables is Figure 1. According to the
information in Study 1, these readings were taken after a period of 7 days, so we can
disregard that bit of information from the question. Now, the question asks about BGO (II),
which is represented on Figure 1 by the darker of the two bars. According to the figure, as
radiation level increases, crystal volume increases. Therefore, it is reasonable to assume that
the volume of a crystal with a radiation level of 300 rads will be greater than that of a crystal
