<p>9-92-6-19 90-53-16 16-1-22^-1</p>
<p>Decipher now. XD. My feelings now that I got 40/75 on a multiple choice test. That’s about a 4, right?</p>
<p>Bump. does anyone know the scoring for the AP Chem exam? such as multiplying coefficient in front of MC and adding up MC and FRQ and such to get the raw score, out of 160… and Beta_fist yes that translates to a 4, assuming that you perform similarly on your FRQs. You are better off than many of candidates and I am sure you are going to get 4 or even, a 5.</p>
<p>As for Oceanangel’s post, here’s an add-on to supplement your missing lab for Beer’s Law:
[Beer’s</a> Law - Theoretical Principles](<a href=“http://teaching.shu.ac.uk/hwb/chemistry/tutorials/molspec/beers1.htm]Beer’s”>Beer's Law - Theoretical Principles)</p>
<p>Does anyone know of any good websites or anything that review acids and bases? I have such a mental block against them, and I don’t want to get the equilibrium FRQ completely wrong.</p>
<p>@zzxjoanw3 - NaHCO3 is the chemical name for baking soda - and it’s base! so that would be the safe and practical way to treat an acid splash (since people use it in the kitchen all the time, obviously it’s not dangerous or anything)</p>
<p>using a strong base like NaOH to treat your skin is unsafe because it can cause burns, scars, blindness in the long term, etc…</p>
<p>the other choices should easily be eliminated</p>
<p>As for your question about the spectrophotometer, the key is that it’s a “visible-light spectrophotometer” so it’s something to do with color. The spectrophotometer measures color intensity so it can determine the concentration of colored solutions like Cu(NO3)2 (blue solution). But measuring the color intensity will not tell you anything about conductivity or ions in a mixture, so the correct choice would be A) I only.</p>
<p>Hope this helps!</p>
<p>Thanks beta, youre a life saver. And Ben, i’ll shoot you a message if its not too much trouble sending me the tests. still at the collection phase of the studying process lol</p>
<p>And another question. do you guys think it’s worth if I study for psych. now or should I just head over there and wing it? Psych. is the afternoon exam on tuesday…and i’m hoping I can easily pull off a 5 there. unless, of course, I super slack these next couple days and end up underperforming in psych. because of too much time spent on chem.
also, too late to request a late-testing session?</p>
<p>Ahh thanks for the help on those problems, guys! I’ll be back soon with more questions. :p</p>
<p>Here are some practice problems for you guys:</p>
<ol>
<li><p>Which one of the following reacts with water to form a strong base?
(a) Lithium
(b) Bromine
(c) Helium
(d) Fluorine
(e) Iron</p></li>
<li><p>Describe a Lewis base.</p></li>
<li><p>What is the coefficient of OH- when the following equation is balanced and expressed in the lowest whole number terms? </p></li>
</ol>
<p>Li3N + H2O -> Li+ + OH- + NH3</p>
<ol>
<li>a) Lithium</li>
<li>A lewis base is a substance that donates an electron pair.</li>
<li>3</li>
</ol>
<p>1a) Li</p>
<ol>
<li>A Lewis base is one that donates a electron</li>
<li>too lazy lol</li>
</ol>
<p>No, lemone. A Lewis base does not donate a proton. It donates an electron pair. A Bronsted-Lowry base accepts a proton.</p>
<p>Can someone help me with this weird question? It’s from PR</p>
<p>What is the boiling point of a 2m solution of NaCl in water? (The boiling point elevation constant, kb, for water is 0.5C/m)</p>
<p>I got 2, but the book says it’s 102…</p>
<p>@New, I meant electrons, but I typed in protons for some reason.</p>
<p>Whew! I actually got 45 right and 20 wrong, but the raw score is 40. I can relax a little now, since I mainly just want at least a 4. </p>
<p>Dang, I enjoy studying this stuff…why didn’t I study during the school year? (the slacker in me says it’s because I was always the top of the curve and wouldn’t have gotten a better grade… =/ )</p>
<p>I’m ready for next year…college chem!</p>
<p>
</p>
<p>Step back and look at your question. Question yourself about the validity of your answer. You claim to have gotten a value of “2,” and although your math is correct, your reasoning is not. Is a 2 M solution of NaCl going to have a boiling point of 2 degrees? Traditionally, when solutes are added to a solvent, the boiling point rises. </p>
<p>You have calculated the boiling point elevation, not the boiling point. It will serve you well to analyze problems conceptually when you don’t arrive at the correct answers.</p>
<p>
</p>
<p>Good job!</p>
<p>^=Delta
*=standard temp</p>
<p>Why is ^S* of F- and of OH- negative? These are the only two substances in the appendix of my book that have negative entropy of formation values.</p>
<p>Here’s a question from a past test I had in class:</p>
<p>Of the elements below, which has the largest FIRST ionization energy?
a) Li
b) K
c) H
d) Rb
e) Na</p>
<p>From the 2008 AP Exam:</p>
<p>Which of the following measures of concentration changes with temperature?
a) Mass percentage
b) Mole fraction
c) Molarity
d) Molality
e) ppm by mass</p>
<p>Beta–when they form, they must move from a state which has more microstates.</p>
<p>For F-, the reaction would be (1/2)F2(g)–>F-(aq)
And for OH-, the reaction would be (1/2)O2(g) + (1/2)H2(g)–>OH- (aq)</p>
<p>Since there are more moles of gas on the (edit) REACTANTS side, it makes sense.</p>
<ol>
<li>C (Hydrogen)</li>
<li>C (molarity)</li>
</ol>
<p>H?</p>
<p>Molarity</p>