SAT 2 Chem Discussion May 2 2009

Test Preparation SAT Subject Test Preparation
81

<p>Yes, it is where they are both at equilibrium. I’m not sure on the exact letter, but it was on the line near the bottom left corner.</p>

<p>Also, the question about hydrocarbons was TT. What was the second question again? I can’t seem to come up with it so it could still be TTCE.</p>

<p>I believe I put TF for that question because the reason said that AlCl3 was a bond between two nonmetals and NaCl was a bond between a metal and a nonmetal and Aluminum is a metal so it was still between a metal and a nonmetal.</p>

<p>Na is more “electropositive” than Al so that is why it exhibits more ionic bond character than Al with Cl.</p>

82

<p>AlCl3 is a bong between two nonmetals?
I’m pretty sure Aluminum is a metal
I looked at the charges on them. Al has a 3+ charge while Na only has a +1 charge</p>

83

<p>Does anyone remember how many questions were related to the phase diagram? I just realized I completely mixed up the liquid and gas parts in my head. :(</p>

<p>What is the usual number wrong for a 800?</p>

84

<p>how many can you get right and omit for an 800?</p>

<p>I omitted 2 so how many can I get wrong to get an 800?</p>

<p>I got the brass question and the strongest Bronsted-Lowry base (I put NH3 :frowning: one wrong.</p>

<p>What was the unsafe chem practice one? I put the gas fume hood b/c not all gas-producing reactions produce toxic fumes that will cause intense pain suffering and disfiguration.</p>

85

<p>The reason said that Al was a nonmetal and that was why it was false.</p>

<p>It was pouring water into acid because you could splash it. You always want to use a fume hood in case.</p>

<p>Okay I have to go. I’ll be back on here later to discuss and answer.</p>

86

<p>There were 3 questions relating to equilibrium</p>

<p>And yeah, whats the grading curve for this test? I’m satisfied just being in the 760-800 range</p>

87

<p>Are you sure the reason said Al was nonmetal?
I remember the question asking whether NaCl had more ionic character than AlCl3 then the second part saying it was because Al was more electronegative than Cl
but maybe im remembering wrong</p>

88

<p>You’re right. Not all gas fumes are toxic. Would you take the chance, though? The fume hood one was right.</p>

<p>There were either 3 or 5 questions related to the phase diagram.</p>

89

<p>Yeah, the second statement said it was because Al was a non-metal.</p>

<p>You’re remembering something about acidity and dissociation from another question…where it said something about Al’s ionic character.</p>

<p>-There were 3 questions on the phase diagram.</p>

90

<p>brass is an alloy of copper and zinc</p>

91

<p>What’s the answer to the one about nonmetals v. metals? I put something about oxides.
Also, was the semiconductor one Al?</p>

92

<p>Yeah, it was oxides.
The semiconductor one was germanium, I’m pretty sure. Metalloids are semiconductors</p>

93

<p>what about those in the beginning where a gas was created and a complex ion formed</p>

94

<p>There was a question about adding NH3 to NH4Cl, and I thought it was easily KOH, but then I started thinking about common ions and confused myself. Could anyone explain it?</p>

95

<p>Glass - SiO2
Acid rain - SO2
Ozone destroyer - The compound with the F (haloalkane)
Brass alloy - Zinc
Complex compound - Reaction with NH4NO3 as product
Metalloid semiconductor - Germanium
Nitrogen orbitals - F, T
Eudiometer - T, F
Most basic bronsted-lowry - OH-
Unsafe procedure - Slowly adding water to acid
Nonmetals vs. Metals - Acidic oxides
Accurate measurement - Buret
Last one with the H2 and O2 gas - Same partial pressure
Most heat produced - 1.0M HCl
Reaction that produces a gas - The one that produces H2CO3?
Phenolphthalein + excess NaOH + HCl - ??</p>

96

<p>The gas created was the HCl + the compound that had a carbonate ion. Strong acid + carbonate ion=carbon dioxide
The complex ion was the one with copper nitrate with ammonia added to it, I think?</p>

<p>Ohh, the one you’re asking about, I’m not sure sure about. It was asking which one would give a pH change in the same direction. NH4Cl is acidic because NH4 is the conjugate ion of a weak base, and so adding NH3 (basic) means the pH increases. I also put KOH because it would cause an increase in the pH</p>

97

<p>

This one was a haloalkane.</p>

98

<p>what about the one where (i dont know the exact numbers, trying to remember) 2L of 1M NaOH is added to 1L of 1M HCl, what is the solution going to look like?</p>

99

<p>Why is the Eudiometer one not TTCE</p>

100

<p>Complex ion - Pretty sure this was the Ba + SO4 solution, as BaSO4 precipitates</p>

<p>Reaction that produces a gas - I remember putting a compound with Calcium. Don’t metals produce hydrogen gas in solution?</p>

<p>Phenolphthalein + excess NaOH + HCl - ?? - I put clear pink solution, as it is basic. NaCl is soluble, so there shouldn’t be any precipitate…</p>

<p>For the NH4/NH3 thing, I also put KOH. Got a little confused though, and I’m unsure.</p>

<p>Also, I put TTCE for the eudiometer. It was worded strangely though.</p>