ACT Past Papers with Answers

If the CO2 input from human activities could be reduced to zero, Scientist 2 would rnost likely state that this change Wo￿ld have which of the following resulting effects, if any, on glob21 climate? This change would: cause an immediate increase in global tempera- ture. cause an immediate decrease in global tempera- turc. accelerate the breakdown of the ozone layer. ACT-610 36 GO ON TO THE NEXT PAGE. 40000000004

If Scientist 2 is correct, which of the following ￿raphS would best represent the relationship between solar energy output and Earth's average suiface tempcratllre tiends over the past 18,000 years?

According to the viewpoint of Scientist l. which of the following graphs best represents the increase in 2tmos- pheiic CO concentration over the past 200 years? Key - Earth's average surface ternpera￿re so12r energy output . 200 100 years before piesent 200 100 years before presellt 18,OlX) 200 100 years before piesellL 200 100 years before present ye2rs beLore present

times greater 18,IK)O ye￿S before present ..ACT-61 D 37 GO ON TO THE NEXT PAGE. 40000000004 Passage 11 Key oils boiliug above 340°C middle distillates boiling between 170°C and 340"C gasolillt boiThng below 170°C Crude oil contains thousands of chemical compounds_ To Dbtain commercially useful Co￿pOundS, crude oil is dis- tilled in afrnctionafing rowgr (see Figure l). The crnde oil is first heatcd to 400°C ill a furnace, then pumped into the fiactionating tower. As vapors from the oil rise, they cool 2nd condepse. Fraclions are collected at different heights in the tower. Each fraciion contains a mixture 'of hydrocar- bon molecules with similar boiling points. Table I shows information about somc of the fractiODs thal can be col- lected. Figure 2 sbows tbc compositioll of crude oils obiained in 6 different geographic Jocations. 100 60 40 natural gas tTt 20 'gasoline kerosene fuel oil Crude Oil Sample fractionating tower - 11 lubricatillg oil Figure 2 Figur& 2 adaptod from The Nevv Encyclopaedia Britannica. @1986 by Encyclopaedia Brilann ica. I nc. crude oil residue fLunacc Figui'e I Figure 1 adapted from American Chemical Soci8ty, Chei77Com.' Chgmistry In the community, 2nd 6d. (Q1993 by Arnerican Chemical Society. 'Table I

Suppose ozone is a greenhouse gas produced by human activities, Scientist I would most likely agree that if increases ill stratospheryp ozone collter,t contribiitp, t the current global warming, these increases do so . because ozone.. can be clianged to oxygen through chemical reac- tions in the atmosphere. Iost to space. is the major gaseous component of Earth's atmos- phere. lar mass of CO years before present

Scientist 2 would most likely agree that, compared to" the amount of CO that human activities put into Lhe atmosphere each year, the amount put into the atllios- phcre each year from sources other than human activi- ties is how many tin)es trreater?

According to the information in Table I, hydrocarbon olecules each having 14 caTborA atoms would most likely be found in which of the following fractions . . J. Lubricatin£r oil Typical llurllber of carb'on atoms per molecule Approximate boiling range Fraction (°c) <20 40-200 200-300 250-350 300-400 Natural gas Gasoline Kerosene Fuel oil Lubricating oil 1_4* 5-12 12-16 15-18 16-24

.Based on.the data in Table I, a fraction containing a ixturt of hydrocarbons ranging in size from 8 to ' 14 carbon atoms per molecule would rnost likely have a boiling range: ' A. below 20°C.. above 250°C. *This range indicates that natural gas iypically contains a mixture of different hydrocarbon molecules iangino It2 size from I to 4 carbon atoms. AGf-61 D 38 GO ON TO THE NEXT PAGE. 0000000004

Based on the information in Figure l and Table I, a fraction containiIig a hydiocarbon that has 7 carbon atoms per Tnolccule.would most likely be collected: near the top of the fractionating towei. in the middle of the fractionaiing tower. lle21 the bottom of the fractionating tower. in the fuTnace.

Based on the information in Figure l and Table I, hydrocarbons found in the residue most likely contain: I to 6 carbons per molecule. 7 to 12 carbofjs pei molecule. .C. 13 to 18 carbons per molecule. more than 18 carbons per moLecule. ACT-610 39 GO ON TO THE NEXT PAGE. 40000000004 Passage 111 Study 2 The students repfaced the 1,000 [2 Tesistor witb a 10,000 A resistor and repeated the procedure used in Study l. The iesults are shown ID Table 2. An RC Gircuit contains a resistor, a capacitor, and an input volt'age source. Some studenls studied RC circuits cont&ining a source of AC (alternating curreul) voltage. Frequency, in hertz (Hz), is.related to the llumber of timeslsec the highest voltage is attained. The measured input voltage from che AC source was the sane in Studies 1-3. Table 2 Frequency Gain across l UF capacitoi Gain across , I 0,000 Q resistor (Hz) Siudy I A circuil was assembled using a 1,000 Q (ohn]) resis- tor, a I ￿lCrofa[ad capacitor (microfarad [kLF] is a unit of capacitlnce), 2 voltmeteis for toeasuring output voliages, and an AC input voltage source (see Figurc l). 10 io, io, io, io, 10

In Study I, the same gain was obtained across the resistor and the capacitor at which, if any, of the fre-" quencies tested? Table I

Based on Studies l and 2 at 10 Hz, replacing the 1,000 fj2 resistor with the 10,000 [2 resistor changed Ibe ll)easured output voltaoe across: the resistor onjy neither the resistor nor the capacitor. Frequency Gain across l capacitor Gain across 1,000 n resistor (Hz) 10 io, io, io, io, io, ACT-610 40 GO ON TO THE NEXT PAGE. 40000000004

In Study.3, cornpared to the gain &cross the capacitor, the gain across the resistor was: always greater. always smaller. quencies. quencies.

In Study 2 at l O Hz. if tht measured input voltage was

In Study I :with the Olltput voltage measured across the resistor, a gain of 0.05 would most likely bave been obtained at a fiequency between: l Hz and 10 Hz. 10 Hz and IO, Hz. ACT-61 D 41 GO ON TO THE NEXT PAGE. 40000000004 Passage IV Study 2 The ash from the burned waste in Study I was ana- lyzèd for Ihe presence of several substances, iJ]cludiDg ercury a]]d lead. Table 2.shows the measured concentra- tions in the ash and the established litnit that, if exceeded foT ally one of the substances, means the satnple of ash would be considered hazardous. Burnintr household waste in n]etal barrels can release harmful émissions {airborne gases .and particulates), including SO , CO, NO , dioxin, lead, and mercury. The reIiiainiurr"2sb also may contaill toxic subsiances. Two studies examined these emissions and ash. Study I Two hundred pounds of hollsebold waste designated for burning was collected from 12 households. The waste was placed in a metal barrel located under a hood that col- lecled emissions (see Figure l). The waste I4Tas burned for 2 bollis at 400°F to 500°F. The average reduction in the weight aud the volume of the origillal waste aft¢r burning was 58 Io and 70%, respectively. Table 2 Measured . concentration (LnglL) Established conccntration limit Substance (mg/L) Arsenic Barium Cadtnium CILrornium Lead Meicury .Selenium 100 hood Figure and tables adapted from Chris Burger, "Emission Character- islics ol Burn Barrgls. Q)1994 by Patrick Engineering, Inc. barrel Fi lure I The concentrations of cmissions, in parts pei fflillion (ppm), were measured. Table I shows the results and the established maximum allowed concentrations in emissions froTn incinerators (facilities that buru large quantities of hollsehold waste).

Mercury is a liquid at room temperature. Based on the reslllis foi rnercury in Study l and the design of that study, one would concllldc which of the following about the properties of mercury? The temperatures of 400°F to 500°F that were.reached in the. metal barrel were sufficient to change some of the mercury from a: solid to a liquid. Table I Measured concentration in barrel emissions Maximum allowed incinerator emission concentiation Ernission (pprn) 343,000 (ppm) 232,000 l. Particulates II. Gases so, co NO, Dioxin Lead Mercury

The tnore toxic a substance, the sinaller the concentra- tion at which it is consideTed ha2ardolls. According to this information and Study I", which .of the listed gases is considered the most toxic?

If Study 2 had beell repeated using thc waste from 15 househojds inste&d of 12 households, the resulting measured concentration for each substance in the repeated Study 2 would most likely have been: Knuch higher than the iespectivc conceDttation i the original study. similar to the respective.concentration in the origi- nal study. touch lowei than the rèspeclive concentiation in the ori(riDal study. approximately zero for all subst&nces.

Which of thc following statements about the concen- trations of Sllbstances in the ash from burning waste in metal barrels is supported by the results of Study 2 ? The ash left after burning waste in metal barrels: contained h12ardous ,'concentrations of all the tested substances. contained hazardous concentrations of mercury and lead only. the tested substances. Cllry or lead.

In Experiment 2 on Day 600, the re12tiN'e positions of the Sun, Earth, and Venus were closest to those shown in which of the following diagrams?

According to the llnceTtainty in the measurernent of g at a wavelength of 3.1 cm. the true value of g was most likely between.. i aiLaeL and 2. 17 arcbec. Day Day

Suppose, on Day O in Experiment 2, Ihe reliiive posi- tions of the Sun, Eaith, and Venus were as showT] in the diagra￿ b¢low. The graph of the delay versus Day would hal'e looked most like wbich of the following gIaphs? Day Day

During Experiment 2, the largest delay in the radio waves was produce(i when the radio waves p(Lbsea'. way to the Sun and oll their return to Earih. cIDsest to the edge of the Moon both on their way lo the Sun and on their return to Earth. to Venus and on their return to Earth. closest to the edge of the.sun both on their way to Venus and on their return to Earth.

The Sun w.as used in both Experiments l and 2 most likely because the Sun.. is tbe biightcst object in the solar system. emits both visible light and radio waves. is the most massive body in the solar system. is easily viewed during a SO1￿ eclipse. ACT-e1D 45 GO ON TO THE NEXT PAGE. 40000000004 Passage Vl The concentration of dissolved oxygen (DO) in river water affects the fish in the rivcr. Many freshwater fLsh specics, including crappie.. percb, and bass, require a mini- mum average DO CODcentration of 5 parts per million (ppm) to thrive. Other fish, sllch as carp and gar, can toler- ate averd£Te DO concentrations as low as 3 ppm. Table I shows the DO concentration at saturation foi water at vari- ous temperatures. Figures l and 2 show the measured changes in a river's water le￿Perature. and DO conceDtra- tion, Tespectively, over a 24-hour period ill midsllmmcr. Table 2 shows how the DO conccntration affects fish species in & river. 8 10 12 2 4 6 8 10 12 2 4 6 P.M. Figure 2 Table 2 Table I DO Water ternperature DO concentration (pptn) at saturation

River watei is ofien used in industri&l processes and is then returned to thc river much warmeI th&n when it was removed. Based only on the information in Table I, why would Lhis warnied watei be a potential danger Lo fish populations? The warmed river water ost likcly has: a ELigher DO concentratiOII than does the cooler river wateI. a lower DO concentration than does the cooler river watei. water. a DO concentration of zero, u 23 22 21 19

Accordillg to Fioure l and Figure 2. which of thc fol- lowing best describes what happens to the water tem- perature and the DO concentration between 2 A.M..and 7A.M.? Waler teruperature Steadily increiscs Steadily decreases Remains the same Remains the same 8 10 12 2 4 6 8 10 12 2 4 6 P.M. time DO toncentration Rernains the same Steadily decreases Remains the same Steadily incieases Note". This river is located in a te￿perate region (cold winters, waTm SUULD]ers). Fioure I Acr-e1D 46 GO ON TO THE NEXT PAGE. 40000000004

B

Which of the following graphs best repiesents the rela- tiollship between Mpatet Lemperature and DO concentra- tion at saturation shown in Table 1 7 15 10 10 20 watei temperatUTC (°C) 30 15 10 10 20 30 water tezllperature (°C) 10 20 water temperature (°C) 30 15 10 LO 20 30 water.texnperature (°C) ACT-fjID 47 GO ON TO THE NEXT PAGE. 40000000004 Passage Vll The male-to-female body masj ratio (MFMR) of a species can be calculated as follows: In this equation, M. is the aver2tre body mass of adult ales and F. is the averaoebody ￿asS of'adult females. The figure shows the MFMR of some species within 4 primate groups.. apes and humans. Old World inollkeys. New World monkeys. and prosimians. A species with an MFMR of l is monomorphic with respect to body mass. A species with an MFMR dÉfferent than l is dimorphic with respect to body mass. (Note: In the figure, MFMR Values are calculaLed to the nearest tenth.) Apes and humans gibbons H - humans - chimpanzees orangutans Go - gorillas New World monkeys 10 sakis owl monkeys woolly ￿Or]keYS Ho - howler mODkeys capuchin mODkeys Goeldi's monkeys rnarmosets + tatnarins Old World monkeys Le = leaf monkeys G - guenons ProsimiaDS 18 16 T - tar5iers Gl - galagos Lo - lorises aye-ayes in(Irids D - dwarf lemurs L = true lemurs Gl tatatata J4 12 10 Gl Gl Figur8 adapted from Steve Jones, Robert Martin, and David Pilbeam, eds., The Cambridge EncyGlopedia of Human Evolution. Éyg92 by Cambridge University Press. ACT.610 48 GO ON TO THE NEXT PAGE. 40000000004

AccoTdin£ to, the figure. the body mass of the averaoe adult tnale orangutan is how many times greater than the body mass of the average adult fen]ale orangutan? .H. 1.6