<p>I just talked about the charges and the size of the ions when discussing why one ionic compound was stronger than the other.</p>
<p>Yeah, structure one was the right one.</p>
<p>I put Cu was the element... Weird.</p>
<p>Cu is right</p>
<p>i didnt get n=4 for any of them..
how did u get that??</p>
<p>EDIT: n=3 b/c they are all in the 3p orbital</p>
<p>and yeah, 122 was weight for both molecular and empirical. at least that's what i got.</p>
<p>Cu is the element. Mg has an atomic mass of 24, and Cu has an atomic mass of 62.55. Also, for this I put that the more abundant isotope was the one with larger atomic mass. Because the isotopes averaged (w/ weighting) equaled 62.50, but because of the .05, weight must lean toward the larger atomic mass. Did anyone else get this?</p>
<p>Haha, I got structure one, I just put "because it has higher formal charge." lol, totally wrong.</p>
<p>For #7, I put:</p>
<p>a)</p>
<p>(i) No, the other molecule ALSO had dipole-dipole...didn't it? what was the other molecule? I only remember F. But there was a lone pair, so I think it had to be polar, even if it was covalent. yeah.
(ii) So difference here is in IMF, except that NH3 has H bonding and the other doesn't. </p>
<p>b)</p>
<p>(i) Both are ionic bonds
(ii) Eh, I forgot the other option. It was NaCl and what, KCl? I put NaCl because it is more electronegative = more ionic character = stronger ionic bond. Is this OK? I'm seeing coulumb's law, but I remember on the SAT II there was an MC about which has the highest ionic character and it was CsF b/c there was greatest diff. in electronegativity. Doesn't that mean the ionic bond is also stronger?</p>
<p>c)</p>
<p>(i) All are n=3
(ii) More protons = greater pull, harder to lose electron. Yeah, not adding shells, so same distance from nucleus, which is more + charged. </p>
<p>d)</p>
<p>(i) Magnesium or something. Dont remember...
(ii) 64.93, closer to element average amu </p>
<p>yay!!! Oh, what did you guys put for the SPLINT test!?! (and does anyone know why SiO2/explain well why SiO2 does not do anything in water? cuz I know pH = 7 because SiO2 is glass...)</p>
<p>this is what I put...it was pretty much bsed it but:</p>
<p>O2: increased flame b/c oxygen fuels fires. thus may get hotter/brighter , ignite embers.</p>
<p>N2: Eh, forms brown NO2. Splint cools down b/c O2 is consumed.</p>
<p>H2: Forms water. LOL. Splint cools down b/c O2 is consumed in rxn, and b/c water is wet!</p>
<p>Isn't a 3 just like 33% ?</p>
<p>no.. more like a 40%</p>
<p>64.93, closer to element average amu this is wrong. it's devastating cuz i totally put that too. but the unweighted average would be 63.93, not 63.5, so that weighted is 63.55 and so it's lower and thus closer to 62.93, rather than 64.93. Doesn't that bother you? This is supposed to be like super easy 1st day chem problem too. GAHHHH</p>
<p>ebonytear, how is that wrong? I dont get it?</p>
<p>what are you talking about??</p>
<p>periodic table tells u the absolute mean...</p>
<p>the one w/ the absolute mean is most abundant..</p>
<p>no. it is weighted mean. if there is 90% 65 amu and 10% 63 amu, it will def. be basied to the 65 amu. that's why you have these problems in the first place - and how you can tell which isotope is more abundant - by the weighted average. If it were absolute mean it would be 64.0, which it is not.</p>
<p>Ok. Think about it this way. You have 64.93 and 62.93 as the two different isotopes. The weighted mass given on the periodic table is 63.55. The absolute mean - the unweighted average - is 63.93 (difference between 2 isotopes is 2, so add 1 to 62.93 = 63.93). The weighted average is less than the unweighted average, so 62.93 must be weighted more heavily - i.e. more abundant - for it to be lower.</p>
<p>naw Cu is not the element that turns blue in NH3</p>
<p>I looked it up on my text book. Only alkali ions turn blue because their 1 electron gets solvated by Ammonia molecules or something like that.
F*!^k I got that question wrong</p>
<p>sorry if someone's already discussed this...
for #8, part d., the electrolysis, was
anode: I- → e- + I (s)
cathode: Na+ + e- → Na(s)
?? and ∆G positive?
thanks</p>
<p>For Kinetics problems, all order were 1 right?</p>
<p>and Y axis was ln[x]
right??</p>
<p>I- → e- + I</p>
<p>I don't think that Iodine would go. Water would undergo the electrolysis before the Iodine.</p>
<p>G = negative (G = -RTlnK)
S = positive
H = negative
anode: The Na, because it has the greatest oxidation potential (2.71)
cathode: The most positive H20 (1.23V)
oxidation at the anode
sign is positive, obviously for it to be spontaneous, G = -nFE, E will be applied.</p>
<p>Edit: flipped cathode/anode</p>
<p>i did practice problems and it ALWAYS worked out my way...</p>
<p>why are u trying to weigh anything???</p>
<p>You know the absolute mean.. There are tons more isotopes..
and you know the masses..
you just see which ones are closer...</p>
<p>its pretty normal no matter what...
the closer to mean = more abundant</p>
<p>sorry I meant I- → e- + I2 (g)
why isn't that right? what did you put?</p>
<p>arsenal:</p>
<p>anode: The Na, because it has the greatest oxidation potential (2.71)
cathode: The most positive H20 (1.23V) because it has the greatest reduction potential</p>
<p>yeah. Variance, but 62.93 is closer to the mean. 64.93-63.55=1.38 BUT 63.55-62.93=.62. OK, so that's way simpler, but yea. same answer. 62.93 is more abundant.</p>
<p>anyone have solutions to all the essays?</p>