June SAT II Chemistry Thread

<p>I’ve been consistently getting 680-700s on Kaplan tests and SN Tests… Should I be worried?</p>

<p>Which bond is stronger: ionic or covalent?</p>

<p>^ Covalent. Covalent bonds are shared electrons, whereas ionic bonds are attracted through the positive and negative charges after one atom gives/receives an electron.</p>

<p>Biology: Covalent</p>

<p>Chemistry: Ionic</p>

<p>Oh… Biology.</p>

<p>I really don’t understand this question, nor Barron’s explanation of it…</p>

<p>How many grams of H2SO4 are in 1,000 grams of a 10.% solution? (1 mol of H2SO4 = 98 g)</p>

<p>It depends. For example, diamond is a covalent bond, and it’s much stronger than an ionic bond.</p>

<p>So how would Hydrogen bonds compare with covalent bonds? O-o. would they be even weaker than ionic bonds?</p>

<p>and could somebody answer my questions? :)</p>

<p>bandgeek156: hydrogen bonds are the strongest. whnever u see a bond question always start with hydrogen bonding.</p>

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<p>As far as I know, ionic bonds are stronger than polar and nonpolar covalent bonds, but not as strong as covalent network bonds.</p>

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<p>You can’t really compare those: Hydrogen bonds occur in between molecules while covalent bonds occur within molecules.</p>

<p>yeah like pi said above me, ionic/covalent bonds =/= IMFs (aka Hydrogen bonds)</p>

<p>guys i still can’t get a hang of nonpolar/polar. reading explanations from review books don’t make sense to me. can someone simplify it for me?</p>

<p>Polarity basically means that one atom has a stronger pull on the electrons. This usually has to do with a difference in electronegativities within the atoms (electroneg is the element’s ability to attract electrons). Like in water, there is a much bigger difference b/w Hydrogen’s and Oxygen’s electroneg, so there are polar bonds between hydrogen and oxygen, and so water becomes a polar substance. Note that, a substance can be nonpolar and still have polar bonds (not sure how this works but it was emphasized in Barrons). Electroneg diff of about .4-1.6 makes something Polar Covalent.</p>

<p>just look at the difference in electronegativities (that 0.3, 1.7 thingie) also make sure that the dipoles dont cancel each other out (Ex. CO2)</p>

<p>@vbpointer42- can you explain how a substance can have polar bonds but not be a polar compound? i think it has something to do with canceling out polar substances?</p>

<p>haha well at least I’m not the only one freaked out :D</p>

<p>@vbpointer: JK. I found the answer to my own question. It basically has to do with shape (i.e. linear, tetrahedral) which cancels out the charges
[url=&lt;a href=“Yahoo | Mail, Weather, Search, Politics, News, Finance, Sports & Videos”&gt;Yahoo | Mail, Weather, Search, Politics, News, Finance, Sports & Videos]Why</a> can some molecules have polar bonds, but overall be nonpolar molecules? - Yahoo! Answers<a href=“if%20anyone%20is%20interested%20in%20reading%20the%20explanation…”>/url</a></p>

<p>yeah that’s correct girlrockingguna. Sorry i was reviewing a practice test and didn’t get to respond >.<</p>

<p>does anyone know how to do this problem?</p>

<p>If you have 0.15 equivalents of H3PO4, how many moles of H3PO4 do you have?
ans. is 0.05</p>

<p>O:</p>

<p>Barrons is still giving me 560. :/</p>

<p>ilyana: are u reviewing ur mistakes? it definetly helps. i started my first diag with a 560. second one went to a 600, 3rd one a 620 and lastly a 650~</p>

<p>keep reviewing ur mistakes. i took a sparknotes one mad quick and on the fly (had like 37 min left xD) and landed a 520(which is mad bad but i didn’t even bother reviewing my test with all that time, or doing the ommited ones, or the ones i said i was unsure of).</p>