<p>I put TTCE for PH3. Mutual repulsion is still repulsion…</p>
<p>A catalyst does what to A + B C?</p>
<p>Speeds up the forward and reverse reactions</p>
<p>i dont think this is right. a catalyst would not speed up the reverse reaction, it would make the K value higher because [product]/[reactant] … thus more product = higher K</p>
<p>But catalysts do not disturb equilibrium. Catalysts dictate how quickly the reaction can reach equilibrium (and sometimes a reaction would have to go in reverse to reach equilibrium).</p>
<p>hmm… i said speeds up forward + reverse reactions. I know that K value only changes when temperature changes (and slightly with pressure) not when catalysts are added, I thtink cause catalsysts speed up reactions, they do not increase the amount of concentration at equilibrium. they speed up how fast a reaction reaches equilibrium. Maybe? I am not 100% positive. </p>
<p>i know they change they lower the energy of activation, so I think that that affects both the forward and reverse reactions… adsfkj ugh</p>
<p>Edit: Ha, jenkster said it first</p>
<p>Ohhh I took so long on this too too…28 minutes on the practice test from '04 but I barely had two minutes to look this one over.</p>
<p>The curve is usually 4 questions = 800, ish.</p>
<p>That second paragraph was a great observation though.</p>
<p>if PF3 trigonal planar</p>
<p>grammar sometimes escapes me.
pf3 is trigonal planar, was there a question about that i forget already lol</p>
<p>I thought PF3, like NH3, was trigonal pyramidal.</p>
<p>PF3 is trigonal pyrimadal (on CB practice test =-))</p>
<p>yeah it’s trigonal pyrimidal because of the extra non-bonding pair on phosphorus. </p>
<p>btw, how’d you find the molar energy (or whatever) for water when you were given the value for Jewels over grams.</p>
<p>ooh yeah its pyrimadal your right! hmm seriously though was that in the TTCE section or mult choice, or what was it</p>
<p>you’re thinking about PH3 i think lol</p>
<p>Yay, I got all of these! =)</p>
<p>But, I realized about ten seconds after the test finished that I chose the graph starting @ the y-axis for the P-V graph. Yuck.</p>
<p>You multiply out by the molar mass for the water question; roughly 18 grams for water times 334 or whatever it was means about 6,000 joules per mole, I think it was choice E. The PF3 question was in TTCE, and I think that question WAS TTCE…</p>
<p>phew i said true about that one! </p>
<p>sparta praha: i multiplied by molar mass of water, 18.02 and got the highest answer there, I think. i could obviously be wrong. but if you do some stoich it works</p>
<p>and does anyone remember what it was asking about in the second section of the ph3 one.</p>
<p>To Sparta Praha:</p>
<p>J/g X g/mol (molar mass) = J/mol</p>
<p>You beat me! But, I got the same answer as you.</p>
<p>what was the one with the amount of energy of making H20 from hydrogen and oxygen</p>
<p>i wrote out how 2H2 + O2 —> 2H20</p>
<p>half of the energy given</p>