<p>@hwjwill: i can confirm that it was indeed forward reaction goes faster and then both are at equilibrium. This has to do a bit with Le Chatelier’s Principle and Reaction coordinates. I’m in AP Chem and we’ve discussed this.</p>
<p>Skalyan is indeed correct. What was the answer to the percent yield?</p>
<p>For question 40 does tube 1 counter both hypothesis?</p>
<p>^I put neither…</p>
<p>in the same section, it asked if Tube 2 supported Hypothesis 1 or 2. Did you guys put 2? If so why? Is it because the line in Tube 2 is in between the one in Tube 1 and Tube 3?</p>
<p>Answer to the percent yield question?</p>
<p>Sammy: Tube 2 supported hypothesis 2 because the band was more dense than the original dna (tube 1) and less dense than entirely new dna (tube 3). This is because each new strand of dna contains one old ssDNA and one new ssDNA.</p>
<p>FutureDoc: The percent yield goes down at any temp.</p>
<p>The question was like 80% = exp/actual. I don’t quite remember but I believe there was 500 being used in the equation. Was one of the answers .4?</p>
<p>^The answer is 400 because 400/500=80%</p>
<p>So lets make a consolidated list for the disastrous last part…</p>
<ol>
<li><p>Which of following is not mentioned?
The effect of E-clois with other bacteria (Not confirmed)</p></li>
<li><p>Tube 2: 50%/50% of two isotopes of nitrogen</p></li>
<li></li>
<li><p>Which hypothesis create a new ssDNA with a old ssDNA something (forgot the wording)
Hypothesis 2, forgot the reason</p></li>
<li><p>Tube 2 supported hypothesis 2 because the band was more dense than the original dna (tube 1) and less dense than entirely new dna (tube 3)</p></li>
<li><p>Tube 1 counters both hypothesis</p></li>
</ol>
<p>Fill in the blanks guys…</p>
<p>I thought it was hard, but I didn’t have to guess on any of them. I rushed a bit on the last one about the DNA, but it was still alright. No one ended up crying in my test room haha.</p>
<p>It was definitely hard. I didn’t even have time to finish the last passage, so I had to fill in random answers on that one. But it wasn’t as hard as the one from June, in my opinion. That was killer and it kept me from getting my target score. Hopefully I can do a little better on the science and keep my scores from the other tests at least the same, so I can increase my score by 1 point.</p>
<p>i thought tube 1 supported neither hypothesis because at that point tube 1 was just initial conditions (nothing happened yet) so it didnt disprove or prove any of the hypotheses.</p>
<p>Syringe Passage
-Lower D means Lower Temp
-All three boiling points
-Graph Increasing (starts at 70)
-Heating in Experiment 1, Coolant in Experiment 2
-Biggest Change from 50 to 19.6
-D Added by 5, 53.3</p>
<p>I tutored about 15 students for this test and my phone started lighting up immediately after the exam. Every comment was about Science. I had worked hard to convince my students that there is nothing inherently difficult about the Science section–it’s just a matter of handling the time pressure and answering mostly straightforward questions. After reading all these comments I will have to change my coaching strategy. BUT, the good news is that the ACT gurus have shown more variability in the past as to how the Science section is graded than any other section. If you look in the Red Book, you’ll see previous Science tests have yielded anything from a 28 to a 33 for missing 5 of the 40 questions. The curve could even be better on this one.</p>
<p>@saidu10</p>
<p>I’m pretty sure the graph is going down.</p>
<p>And wasnt the general consensus that for the boiling point question, it’s only the one that starts with an a?</p>
<p>I’m pretty sure that the answer was all three for the boiling point question</p>
<p>@sammy i think all 3 boiled</p>
<p>but the graph went down right?</p>
<p>this is for the syringe one right? if you look at the chart, the gap of D = 50mm expanded every time. A gas must have evolved from the liquid to expand in that contained space to make it move from 50 to 52 or whatever. since it was in boiling water (around 100C is where water boils) and since there was a gas present to make the syringe expand, the liquid at hand must have boiled at some point to produce the gas to make the syringe expand.</p>
<p>ok yeah that syringe part wrecked me, I probably missed 7-10now. I am so getting like a 25</p>
<p>Actually, there was only one that boiled at a higher temp. than water. I don’t remember the name, but I believe it was choice B. You learn in chemistry that all liquids boil at a certain, specified temperature, and this is 100 C for water. Liquids do not exceed this temp. without becoming gasses, so when the syringes were submerged, the liquids were at their max temp, or boiling point. Since syringe expansion depended on temp. of the liquid, those that expanded more had a higher boiling point and those that expanded less had a lower boiling point. Water’s syringe expanded to around a 62, while two of the options remained in the high 50’s and only one option surpassed water, expanding into the 70’s. That was the option with the higher boiling point. This question was unfortunate in that it needed some advanced chem to answer, and wasn’t really a ACT appropriate question.</p>