December 2010 ACT Science Discussion

Test Preparation ACT Preparation
181

<p>-Metamorphosis for the rock one
-Student 1,3,4 all said CH4 was produced from beneath surface
-The info that hot fluids never existed on Mars would most contradict Student 1
-The introduction that CH4 is not evenly distributed on Mars contradicts one of the student’s hypotheses.
-PPB of 10 billion would be 100 liters
-Rider1, Rider2 (A,B)
-Which things did not start at PT P for 35 sec? 3, 4 and 5
-What was the average speed closests to? 4.0 m/s
-Pupa changed into adults
-Atoms of X was Iodine (I)
-the formula for that acetic acid was Br2CH… (something)
-Carboxylic acid with flourine atom would be even more acidic since the general trend was that the more electronegative the atoms are, the more acidic the molecule is

  • 22%
  • Gravid eggs were females with unhatched eggs
    -Earthquake results in increase of methane release
    -The graph for # 1 was the exponential + linear one
  • They would move toward each other because opposite charges attract
  • All of the 3 balls were given the same initial charge
  • As Qb increased, theta increased
  • Blue absorbaed more orange and yellow absorbaed more violet
    -Potential energy increased since torque increased and work was done to it = conservation of energy
    –The green was a mix of blue and yellow
    -One of the things I think was one color didn’t absorb any light at 4 min
    -He didn’t want to get the same frog again so he tagged them because doing so would skew the distribution toward that of that frog’s
    -The hypothesis was supported because the max was at the mean and not the alternative
    -Majority of trees went through light defoliation
    -1991 would be next peak year for (locust? reproduction)
  • 8% moderate defoliation was 1980</p>
182

<p>idk ): but then it just sounds like if you have more of something it’ll absorb more lol</p>

183

<p>Adam and maniteez, that’s the answer I put as well. Did you guys have any specific reasoning behind your choice?</p>

184

<p>I reasoned that if something is “thicker” it will absorb more light, and also the graph showed that as time went on absorbance went down; I assumed that after time food coloring “settles” (though this would be undetectable to the human eye) and thus allows more light to pass through it.</p>

185

<p>^ Oh ok, hopefully we were right then. :)</p>

186

<p>Maniteez said concentration not exposure.</p>

<p>Ok, let’s skip this lol.</p>

187

<p>Yeah I know. I’m not too worried about this sitting though as I’m required to take it again in March for TN. Though I do hope if I get above say a 32 I can get out of taking the required practice test my school wants me to take on a Saturday.</p>

188

<p>ditto adam. the graph showed that absorbance decreased, and it doesn’t make sense for concentration to increase over time, so i figured it ‘settled’ as well.</p>

<p>for the conflicting viewpoints passage, there was a question about the distribution of the atmosphere and contradicting Student 3…one of the answer choices was “No, because in some areas its less than 10 and others greater than 250” or something like that. was that the right one?</p>

189

<p>That’s the answer that I put Maniteez.</p>

190

<p>^ yea i put that</p>

191

<p>Just so everyone knows, concentration is directly proportional to absorbance since A=abc where a is the molar absorptivity constant, b is the path length.</p>

<p>Also, the “thicker” an object is, the less light is transmitted so I0/I is reduced and since I (transmittance) is inversely proportional to the log of absorbance, absorbance is increased and hence, concentration is also increased.</p>

<p>And yeah, I still don’t remember that question at all, lol.</p>

192

<p>Also, the way that spectrophotometer works is, light is passed through a slit which is passed through a monochromator (prism) and light is split along the visible spectrum (at least in a UV-Vis) and then a computer is able to plot the absorbance as a function of time by seeing how much light is transmitted through the sample.</p>

193

<p><em>patpat</em> I’m sure you circled something. Did you look over your bubbles for empty ones?</p>

194

<p>So let’s come to a conclusion with the absorbing vs concentration question</p>

195

<p>^Nope. lol</p>

<p>No I’m sure I circled something. I just can’t believe I don’t recall that question</p>

196

<p>absorbance and concentration are directly proportional - thats what was stated in the passage. Thus as absorbance increases, concentration increases.</p>

<p>if it said as absorbance decreases , then concentration decreases.</p>

197

<p>scotttenzer,</p>

<p>As H+ concentration increases, so does acidity, which results in a lower PH level. I think your getting OH- and H+ mixed up. H+ increases acidity, OH- increases alkalinity.</p>

198

<p>

</p>

<p>I didn’t have time to read the passage, but I agree with this statement.</p>

<p>

</p>

<p>Actually it’s as the activity of the hydrogen ion increases, not necessarily concentration.</p>

199

<p>oh , yea my lreasoning behind that was wrong.</p>

<p>However, i am somewhat sure that it stated absorbance and concentration are directly proportional. So the higher the absorbance, the higher the concentration (lower absorbance, lower concentration)</p>

200

<p>^Yes…so why does that matter? Did that have something to do with the question? (Sorry, I don’t remember the question).</p>