<p>They were asking sulfur oxidation number -_-.</p>
<p>OH NOOOOOOOOOOOOOOOOO! headbangs and hair-tearing. :D</p>
<p>is the make-up exam going to have the same free response questions? or is it going to have the free response questions on the college board site that says 2006 B??</p>
<p>uhhh that is a stupid question. Obviously they're going to be entirely new ones.</p>
<p>yay............only water is enough. no extra stuff is needed...
and if you add sulfuric acid into calcium carbonate, carbon dioxide is gonna form...</p>
<p>Water is not enough. CaOh is moderately soluble whereas caso4 is totally insol. Naoh is fully sol. and Naso4 is also. Because the so4 is totally insol instead of moderately sol. it is also correct, but the best answer is doing a flame test.</p>
<p>what are you talking about?
i talking about putting calcium carbonate in water, and it will not dissolve
where's calcium hydroxide from?</p>
<p>"Wait I am 100% sure that Caso4 would be a precip... check sol. rules if u dont believe me."</p>
<p>^^^ I put that too...</p>
<p>i know...but i am saying that for that question, simply throwing both chemicals into water is enough to distinguish between them</p>
<p>gyros. Ca(OH)2 isn't an issue here.
CaCO3 is not soluble at all..... the materials were not Ca(OH)2 and NaOH..... it was Na2CO3 and CaCO3.</p>
<p>best answer is either flame test or dropin in water........</p>
<p>yay evilbooyaa...same here</p>
<p>Someone said, "the reaction for Q and water was....</p>
<p>Q + 2H2O --> H2 + Q+ + 2OH-"</p>
<p>Since Q is an element really down the alkali group, it'll react with water to form a superoxide (O2)-. This is according to Brown's textbook (Chemisty: The Central Science), but I've seen plenty of sources say it forms hydroxide as well. Do you think the AP readers would take that?</p>
<p>It's pretty funny watching you guys agonize over this: I did the same thing last year!</p>
<p>I got a 5 on the test. I'm happy.</p>