<p>since people are making official threads for other subjects,why not do the same for chem in october/november!</p>
<p>you can post questions for other people to answer or anything of that sort. I think it will really help us.</p>
<p>I'll start.</p>
<p>What are acid anhydrides?</p>
<p>^
Plural noun. :)</p>
<p>Um... I'll be taking Chemistry Honors 2nd semester, does one need AP chem to do very well on the SAT II in Chem?</p>
<p>Those are compounds that in aqueous solution will behave as acids.</p>
<p>Like CO2+H20=>H2CO3
then H2CO3 <=>H+ + HCO3-</p>
<p>Know your titration curves! :P</p>
<p>^^ ehh what specifically do we needto know about them</p>
<p>yea.. do we need to know the pH from which the curve starts increasing and ****?</p>
<p>Just know how to recognize the general shapes of each and the special points on them</p>
<p>@lolcats4 or anyone else,</p>
<p>This is the first statement of a T/F Q from Barron's.</p>
<p>Decreasing the pressure will cause the water in a pot of boiling water to stop boiling.</p>
<p>Now barron's said it was false, but wouldn't it be true?
Because if pressure & temperature are directly related, then the temperature should decrease if the pressure decreases.</p>
<p>Barron's explanation said that decreasing the pressure will only cause the water to boil more vigorously.</p>
<p>clarification would be appreciated thanks</p>
<p>It is false because at lower pressures, water will boil more easily.
like if you were on a mountain (lower pressure), water can boiler at lower temps than if you were at the bottom of the mountain</p>
<p>No Barron's is right. The definition of boiling is when vapor pressure = atmospheric pressure. The VP doesn't change, but if you lower the atmospheric pressure by going to a higher altitude, then water can boil more easily. </p>
<p>Don't try to use the ideal gas law when thinking about boiling points of liquids! :P</p>
<p>If a solution becomes cold after a reaction, why would it be considered an endothermic process?</p>
<p>wouldn't it be exothermic because heat is lost?</p>
<p>When something feels cold to you, it's because you're feeling a lack of heat. So, if you do a reaction in a glass beaker for example, and it's cold, then the heat energy around and in the beaker is being consumed and you feel that as coldness. This means the reaction was endothermic, because it is absorbing heat. If it was exothermic, you'd be feeling a beaker warmed by the heat energy given off. </p>
<p>Also, when heat is "lost" the reaction is considered endothermic...it's consumed and turned into something else, like chemical bonds. Exothermic reactions are those in which heat is GENERATED by the breaking of bonds.</p>
<p>The melting of ice is endothermic, because when you feel how cold it is you're feeling all the heat being lost to it in melting it. Conversely, freezing water is exothermic, because the water has to give off all its heat. (It's sort of unintuitive)</p>
<p>You can read more here: Exothermic</a> water freezing</p>
<p>Ok, I screw up on this question every time
Why should you dilute an acid by pouring concentrated acid into water, not water into the acid?</p>
<p>^^because when you pour water in a concemtrate acid,it reacts with the water violently and spaters out of the flask.But when you add acid to water the acid gets diluted because water is in larger amount and it reacts with the acid slowly.</p>
<p>A strong acid has a very negative change in enthalpy of solvation: it gives a lot of heat when it dissolves because when it breaks down (a very spontaneous and very favorable change), it loses energy in the form of heat. THis can heat up the solution the point the water can splash. You don't want the ACID to splash on you: you want the dilute water+acid to splash if it does.</p>
<p>Hope that helps.</p>
<p>is organic chemistry likely to show up on the test? It seems like such a huge pain to learn and memorize it and it might not even show up at all. Are others doing it?</p>
<p>Does one need to have ap chemistry inorder to pass the satII chemistry?
Can one instead have a class at a communiy college?</p>
<p>i've taken neither^
Anyone know about organic chem though?</p>
<p>What do you need to know about it?</p>
<p>Just some basic functional groups, what isomers are, and basic reactions (combustion)</p>
<p>But honestly I think remember only like 1 question on it</p>