Jumpngo's ChemII Question Thread (i'll have a lot)

Test Preparation SAT Subject Test Preparation
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<p>Question: Does the Chem II name compounds using the stock system or the prefix system? or both?</p>

<p>Also,</p>

<p>Question: Why is PBO2 => lead (IV) oxide? Can someone work out the math?</p>

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<p>There are no naming questions as far as I know, and you will always be given a chemical formula. </p>

<p>However, PbO2 is lead (IV) oxide because there is a 4+ charge on the lead (each oxygen is -2 - oxygen is ALWAYS -2 except in peroxides and a few other exceptions like diatomic oxygen etc). </p>

<p>For example, you cam have Fe (II) or Fe (III) depending on the charge on the Iron (whether it’s +2 or +3)</p>

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<p>I see. THanks. Just forgot that lead is +4</p>

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<p>Well actually, jumpngo, you don’t need to remember that lead is +4… oxygen is -2 (95% of the time), so you just balance it out.</p>

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<p>^yeah. lead’s oxidation state changes.</p>

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<p>Topic: GAS LAWS AND RELATED PROBLEMS</p>

<p>Question: Are Corrections of Pressure-type questions on the CHEM II? <em>questions that require one to convert water to mercury by dividing by 13.6</em></p>

<p>Question: Why is the energy content higher for reactants in an exothermic reaction? (pg. 116 #4)</p>

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<p>Question: Why is the energy content higher for reactants in an exothermic reaction? (pg. 116 #4)</p>

<p>See <a href=“http://www.saskschools.ca/curr_content/chem30_05/graphics/1_graphics/exothermic.gif[/url]”>http://www.saskschools.ca/curr_content/chem30_05/graphics/1_graphics/exothermic.gif&lt;/a&gt; for an energy graph.
An exothermic reaction releases energy/heat. If the reactants have more energy than the products, than the excess energy is released in the form of heat. If the reactants have less energy than the products, than the reaction needs to gain energy from the environment; this reaction would be endothermic.</p>

<p>Not sure about your first question, although I don’t remember needing it beyond the prep book questions (Barrons)</p>

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<p>ooo. damn, you’re good. You stated it very well. THank you.</p>

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<p>What rounded gas constant do we use in PV=nRT? Is it 0.220?</p>

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<p>.220? The gas constant in PV=nRT is .0821. You can usually round that to .01 to approximate if you realllly need to.</p>

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<p>k. thanks. There is so much material…so what is NOT on the test that is in Barron’s prep book?</p>

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<p>look at a book like PR and compare. Focus on the stuff in PR</p>

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<p>What kind of Barron’s score would be equivalent to a 700 with the real CB test?</p>

<p>I heard -15 was an 800 on the real CB test?.. confirmation?</p>

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<p>lol! no. It’s more like -4 or so for an 800</p>

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<p>lol… alright.
Question: Pure solvent VS Solute (nonvolatile) dissolved in solution on a graph.</p>

<p>Y axis: Pressure ; x axis: temperature; </p>

<p>2 curve line things (increasing) </p>

<p>Isn’t the top curve the solvent, and the boiling pt. decreases when the solute is dissolved in solvent? (because its more random, and takes less heating to reach boiling pt?)</p>

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<p>What kind of Barron’s score would be equivalent to a 700 with the real CB test?</p>

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<p>Is there any source that lists the percentage of each tested area? Like 30% thermochemistry, 20% this, etc for the SAT II?</p>

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<p>er ya.. like every prep book. i know PR does. JUMPNGO, so how goes it. How was ure SAT reasoning? Hey i am taking the SAT 2 Chem as well!!! maybe we can start a prep journal :]</p>

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<p>shall we jumpngo?</p>

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<p>if you would like to. You take charge though, I dotn’ feel like thinking. I’m not really doing anything spectacular. I’m just reading, taking notes, answering the review questions at the end of each section. Theres just so much info… </p>

<p>lol nvm, i see it now. </p>

<p>do you know if theres a lot of math-type questions?.. not basic stoich, but all that other crap…</p>