2008 AP Chemistry FRQS up on CB!!

<p>oh okay..nevermind then..what was products u guys got for
Hydrogen chloride gas is oxidized by oxygen gas.</p>

<p>Some questions.</p>

<p>5B) Would a electronegativy explanation work for why F is greater than O?
5C) I had no idea.</p>

<p>i dont know if an electronegativity explanation would work, because that's still not really explaining why thats just stating "fluorine is the most electronegative element..." but im not the CB and if i were grading it i would give it credit.</p>

<p>I put something like F is more electronegative than O so it has a greater pull on its electrons, making it harder to remove an electron thus making the first ionization energy greater.</p>

<p>i think it would work for 5b..you could have also mentioned smaller atomic radius</p>

<p>i think that gets credit because its basically describing effective nuclear charge.</p>

<p>what about 6 and b?</p>

<p>and answerts to part 2 of all the reaction prediciton?</p>

<p>pyridine will hydrogen bond with water -- dissolving it, benzene has very weak attractions with water so is generally insoluble in water.</p>

<p>complex ion concentration will decrease.
phenolphthalein will turn pink.</p>

<p>got that for benzene/pyridine comparsion...and phenolphthalein will turn pink.</p>

<p>for complex ion i got concentraion stay same..but what was the answer to </p>

<p>If three moles of hydrogen chloride gas and three moles of oxygen gas react as completely as possible,
which reactant, if any, is present in excess? Justify your answer.</p>

<p>i think i had that neither were limiting, but i totally predicted the wrong products so i just made my answer match up with my equation.</p>

<p>yeh i got that neither was limitng too.i htought it was weird...what was ur equation stephenn?</p>

<p>i think it was HCl + O2 --> HClO2 </p>

<p>outside of the box i wrote "this is definitely wrong...."</p>

<p>I said 4HCl + O2 -> 2H2O + 2Cl2. I am fairly confident that this is the correct answer, I don't know what you guys are doing.</p>

<p>o..hahha....i think i got HCL + O2---> H2+CLO-..now i realized that isnt oxidation..i think u mite be right</p>

<p>o wait..yatta ur right..nvm..i did same as you..but iscrewed up balancing..o well</p>

<p>i agree with yatta. i knew mine was wrong but i dont like leaving it blank, since i can't get minus points. so i figured if i put something and then my answer agreed with my reaction i would at least get partial.. y'know?</p>

<p>its sad that i could do the complex ion formation but couldn't get the HCl is oxidized by O2.</p>

<p>hahha..yeh me tooo...wait...were there 6 or 4 ligans for complexation one?</p>

<p>apparently cb accepts both as long as you balanced the charge.</p>

<p>I thought 6B was because one was polar and one wasn't, not hydrogen bonding...</p>