June 2010: Chemistry

<p>Greatest deviation from Ideal behavior or a gas: Low Temp, High Pressure</p>

<p>Yeah I thought the test was easier than I thought it would be. I had to only skip 1, rest I was pretty confident about.</p>

<p>For the Mendeleev one, it was TF.</p>

<p>The second part said “because aluminum and gallium contain the same number of TOTAL electrons”, NOT valence.</p>

<p>Anyone predict the curve for 6 wrong?</p>

<p>10 wrong?</p>

<p>no skips</p>

<p>^but it says something like Mendeleev predicts the “physical properties”.Can we predict the physical property of a substance through Periodic table?..isnt it only chemical properties?</p>

<p>hmm good point, im not really sure.</p>

<p>yeah because the alkali metals are soft, etc.
so im guessing yeah you can
and besides on wikipedia it says that mendeleev predicted the density of Ga</p>

<p>[Dmitri</a> Mendeleev’s predicted elements - Wikipedia, the free encyclopedia](<a href="http://en.wikipedia.org/wiki/Dmitri_Mendeleev’s_predicted_elements]Dmitri"&gt;http://en.wikipedia.org/wiki/Dmitri_Mendeleev’s_predicted_elements)</p>

<p>okay thanks omg i have two mistakes now btw which one was the gas molecules with 1 unpaired electrons each?..omg i need that 800…</p>

<p>The gas molecule with 1 unpaired electon was NH3 I think.</p>

<p>what was the answer to the question where there was a triangle</p>

<p>and three arrows on each side</p>

<p>with 1/2 O2, 1/2 O2 , O2</p>

<p>I think the triangle represented the reaction…</p>

<p>at Aeri, thats wrong. NH3 has 2 unpaired electrons. </p>

<p>@ jooincy, it was 1= 2+3</p>

<p>it was Delta H1 = H2 + H3
because H1=1 and H2 and H3 both equaled 1/2 or .5</p>

<p>was that A? i think that’s what i got.
:D</p>

<p>also, umm…</p>

<p>does it lower the temp. if water gets evaporated???</p>

<p>@Wong: do you remember what the right answer was then?</p>

<p>Hey WongTongTong so which one was it?..hope the curve will be a bit more lenient haha</p>

<p>the correct answer was NO2 or N2O. whichever one has the odd number of electrons</p>

<p>it was NO2 because that the Nitrogen has 1 electron up top.</p>

<p>NO2 has 17 electrons (which is odd), N2O has 16 :P</p>

<p>so what’s the answer to 180 degree gemoetry?
is it co2 or n2</p>

<p>apparently they are both 180 degree.
then what’s the answer</p>

<p>CO2’s the answer, because there are only two atoms in N2 - think about math class. You never have an angle between two points, it’s always three.
At least that’s what I think that’s what the trick was… someone correct me if I’m wrong :P</p>