NOW PASSAGES: ANSWERS AND EXPLANATIONS
Passage I
1 . B Look at Figure 1. At time = 20 min, the % PM is between 20% and 40%. Therefore (A) and
(D) can be eliminated. Since the point lies closer to 40 than 20, (B) is the correct answer.
2 . F The question asks you to determine what the % PM will be for Reaction 3 at time = 8 min.
Eight minutes is a little more than halfway between 5 minutes and 10 minutes. At time = 8
min, the graph lies somewhere above 60%, making (F) the correct answer.
3 . A Compare the % PM at time = 20 min for the reaction with a magnetic field and the reaction
without a magnetic field. At time = 20 min, % PM with a magnetic field was almost 100%
and % PM without a magnetic field was 40%. That means that % PM without a magnetic
field was 40%, or of the % PM with a magnetic field.
4 . G Figures 1–3 do not all express the same relationship between % PM with a magnetic field
and % PM without a magnetic field. Eliminate (H) and (J). Both (F) and (G) refer to Figure
1, and since the % PM increases as time increases, eliminate (F).
5 . C The question asks about % MO as opposed to % PM. If % PM increases in Reaction 3, then
the metal oxide is being used up as the pure metal forms. Therefore, the graphs for % MO
should decrease as time increases, eliminating (A) and (B). For Reaction 3, % PM reaches
100% faster with a magnetic field than without. Therefore, the metal oxide will get used up
faster for the reaction with a magnetic field, eliminating (D) and making (C) the correct
answer.
Passage II
1 . B From Table 1, the work function for Zn is listed as 4.30 eV. Therefore, (B) is the correct
answer.
2 . H Examine Figure 1 closely. At a frequency of 15 × 10^14 Hz, Ni has the lowest Kmax (1.25 eV),
and Al has the highest Kmax (2.1 eV). Thus, (H) is the correct answer.
3 . B As frequency increases, the Kmax value increases.
