May 2010 Chemistry

<p>What was the one about what exhibits most ionic behavior?
CsF, LiF, NaCl, etc I put CsF…
Also, the one with Na2SO4 - x H2O, 9g H2O? I got 10
What was the question with 25 C, and like 10 degrees celcius higher… Did it say faster?</p>

<p>Oh, also, how many would getting like 5-7 wrong be? I answered all of the questions. Should I just cancel and take it again in June? Or would can I submit my highest score to colleges</p>

<p>@dragoneye.</p>

<p>it was 3OH- because they said a SOLID is formed., not a (complex) ion</p>

<p>

</p>

<p>Going by the official practice test’s curve:</p>

<p>Five wrong (none omitted) goes to 780.
Seven wrong (none omitted) goes to 770.</p>

<p>@daboomps
I put CsF for the most ionic.</p>

<p>^ That is correct.</p>

<p>ouch. then should i just cancel and retake in june? or would i be able to send my highest score to any college</p>

<p>^ You can use Score Choice if you want, but some schools (check their Web sites) do not want their applicants to employ that option.</p>

<p>we need more questions !</p>

<p>ok the thing about the gas was like this
the gas was at stp so initial pressure=760mm hg, initial volume was=22.4 l, initial temp=273 K, the final temp, and pressure were given so all u had to do was substitute it int
Pi<em>Vi/Ti=Pf</em>Vf/Tf</p>

<p>Pi=initial pressure
Pf=final pressure
and so on</p>

<p>as far as the rate of reaxn thing is concerned, a to b was faster ,the reaxn was exothermic so the reaxn from a to b was spontaneous whereas b to a was non spontaneous, hence it was faster( got it wrong myself! lol)</p>

<p>Do you remember which choice was correct for the gas question? I think I put either (A) or (B), whichever was like 22.4<em>(300/273)</em>(760/150). Is that correct? I was being lazy on that quesiton and didn’t use any equations; I just eye-balled what felt qualitatively correct. :)</p>

<p>@nkhlgeorge
yea i put TTCE</p>

<p>For the rxn rate question, I put false bc although a to b is exothermic, it doesn’t necessarily mean that it’s spontaneous as spontaneity entails enthalpy and entropy</p>

<p>Spontaneity does not matter; the question was in regard to reaction rate. Activation energy is a direct indicator of a reaction’s rate; lower Ea = faster reaction and vice-versa. The answer was TTCE</p>

<p>Ok here is what I remember</p>

<p>1 2 and 3 each had an answer of N2H4, N2 and HCL
The buret was used twice
Solvation and precipitation were answers for two of them
I confirm the fractional distillation ttce
I put 1/22.4 x 160/760 x 300/273 (I think don’t take stock in my answer though)
one answer was 9 moles to react in the equation
I put ttce for the energy diagram
this page states that reaction rate can be determined to be slow or fast based on energy diagrams [Energy</a> Diagrams: Describing Chemical Reactions](<a href=“http://www.personal.psu.edu/the1/energydi.htm]Energy”>http://www.personal.psu.edu/the1/energydi.htm)
I got a total of 4 ttce
I got ttce for the relative densities of ice and water one</p>

<p>That’s all I can remember at the moment. If I remember anymore I will post them</p>

<p>@silverturtle</p>

<p>I do not believe CsF is the most ionic in that question. I think the answer was LiF because as you remember from lattice energy and the Q1Q2/r equation, the closer two ions are to one another, the more ionic it is. Cs and F were the furthest away from each other of the answer choices.</p>

<p>^ i believe that the most ionic is the one with the greatest electronegtivity difference.</p>

<p>

Not at all. It’s the exact opposite.</p>

<p>Yes, what NewAccount posted is correct. The more polar the bond is, the more ionic the bond is.</p>

<p>Is it just me, or are other people having a really hard time remembering this test?</p>