<p>My strategy is…are you ready for it…know your solubility rules and types of reactions! You can’t do chemistry if you don’t know how to write a reaction for it. </p>
<p>Typically, I don’t do all of my question four in one take. I do part of it, then do five or six. Whatever takes me the least amount of time.</p>
<p>hey, just need some clarification on an oxidation-reduction… just correct me if I say anything wrong please?</p>
<p>So say we have (a galvanic cell constructed using these half-equations):
Cu+ + e- -> Cu E = 0.52 V
I2 + 2e- -> 2I- E = 0.54 V</p>
<p>Since I2’s reduction potential is more positive, it’s more likely to be reduced. Thus, I-, the iodide ion, is the oxidizing agent. Cu+, the cuprous or copper (I) ion, is the reducing agent. Cu, copper metal, undergoes oxidation. I2, iodine, undergoes reduction. The Ecell = .02 V at standard conditions (1 atm, 1 M solutions, 298 K).</p>
<p>^That is correct</p>
<p>Why isn’t I2 the oxidizing agent and Cu the reducing agent?</p>
<p>@mets5life
that’s what I was thinking but I remember putting that and I got it wrong. It was on a website with chemistry quizzes though, so it may not have been entirely legitimate</p>
<p>I2 is the oxidizing agent. The oxidizing agent gains electrons and is reduced. The reducing agent loses electrons and is oxidized.</p>
<p>Sorry half of your post was correct. mets5life is right</p>
<p>Argh. On the Border of a 4/5. On FRQ Question 4 I get almost no points because I just don’t understand how you know which ions are spectator and which aren’t. Like take this example:
Water is added to a sample of pure phosphorous Tribromide. </p>
<p>I got the reactants right, but was completely in the dark for the products…</p>
<p>How do you know?</p>
<p>Mets5life, could you message me the 2008 multiple choice? Thank you.</p>
<p>Can someone give me some advice on the “which indicator is best” questions? I understand that if you have a strong acid titrated with a strong base the best indicator is around 7 ph. But there are those questions where the weak acid is being titrated with a strong base and the correct indicator is around 8-10, but it makes more sense to me that it would be over 13. Can someone explain?</p>
<p>Someone please answer this question and show how they got it. I know the answer so I’ll know if it’s wrong.
-If a metal X forms an ionic chloride with the formula XCL2, then which of the following formulas is most likely to be that of a stable sulfide of X?
A) XS2
B) X2S3
C) XS6
D) X(SO3)3
E) X2(SO3)3</p>
<p>@elmo
When a weak acid is titrated with a strong base, the pH at the equivalence point should be above 7 because the anions that are produced by the acid due to the titration are basic (they hydrolyze water to produce hydroxide ions). However, the anions are weak bases, ex: NO2-, C2H3O2-. Therefore, the pH should only be slightly above 7.</p>
<p>@Dragon, so will you ever have an indicator that activates at a very high pH?</p>
<p>Does anyone have any official multiple choice exams(preferably with answers) past 2005?</p>
<p>@elmo
I did a quick Wikipedia search and found that the highest pH range for an indicator was 10-12. There tend to be more indicators that change color at very low pH. That doesn’t necessarily mean that most weak base-strong acid titrations will have a equivalence point at a very low pH, for similar reasons that I mentioned.</p>
<p>@elmohasagun I believe the difference is that a dipole dipole attraction referes to an individual bond within a molecule, whereas a dipole moment is the charge of the overall molecule.</p>
<p>To clarify, a dipole-dipole interaction acts between molecules. A dipole moment is within one molecule. Dipole-dipole interactions are the result of dipole moments (a.k.a. polar molecules), which are the result of individual bond polarities and molecular geometry.</p>
<p>Hey @mets5life can you send me the audit exam please?</p>
<p>@niquii but for the H2S oxidation, why would it just be H2S -> H? Then there’s no hydrogens in the products. Could you please write the whole oxidation half reaction please? I LOVE YOU AND AM FOREVER GRATEFUL</p>
<p>Can someone explain this from the 2008 MC
In Solid methane, the forces between neighboring CH4 molecules can best be described as </p>
<p>A:Ionic Bonds
B: Covalent Bonds
C: Hydrogen Bonds
D: Ion Dipole Bonds
E: London dispersion forces</p>
<p>Thanks for clarifying that mets5life and superstarlala. Good luck to you both tomorrow!</p>
<p>@Descuff
I would think I’d be XS but I don’t see that as one of the options which is strange. I tried Googling the question but the only match had different options (one of which was XS). Sorry, I hope you find better help :(</p>