<p>9) C
10) E
11) A
12) B</p>
<p>this was a question from the 1999 multiple choice section</p>
<p>tpaschoal, could you possibly provide an explanation?</p>
<p>yeah.
9) strong acid and a neutral solution therefore very low ph.
10) Weak base and a weak acid…neultralize therefore neutral Ph.
11) Base with the conjugate acid, base is stronger than the conj. acid therefore ph is higher than 8.
12) Acid and conjugate base, acid is stronger than the conj. base therefore ph less than 6.
did that help?</p>
<p>For 11) and 12), how do you know which one is stronger?</p>
<p>the acid or base is always stronger than its conjugate.</p>
<p>If the temperature of the solution decreases, then it’s endothermic?</p>
<p>yes, it is taking in heat.</p>
<p>This is also from the 1999 test.</p>
<p>What is the final concentration of barium ions, [Ba+2], in solution when 100. mL of 0.10 M BaCl2 is mixed with 100. mL of 0.050 M H2SO4?
A. 0.00 M
B. 0.012 M
C. 0.025 M
D. 0.075 M
E. 0.10 M</p>
<p>The answer is C, but can someone explain?</p>
<p>Sorry to bump in, but in what situations will I generally be using an ICE chart?</p>
<p>mol BaCl2 :</p>
<p>.1 M = x mol/.1 L</p>
<p>x = .01 mol</p>
<p>mol H2SO4</p>
<p>.05 M = x mol/.1 L</p>
<p>x = .005 mol, H2SO4 is the limiting reagant.</p>
<p>Therefore, .005 mol of both substances will react and form a precipitate BaSO4. However, .005 mol BaCl2 remains, which dissociates into .005 mol Ba+2. However, now that there is .2 L of solution, we divide .005 by .2 to get .025 M.</p>
<p>@Battlecruiser, Equilibirum</p>
<p>alright guys, wish me luck, and godspeed to all of you. :)</p>
<p>God, THAT’S it?</p>
<p>Man, should’ve remembered that BaSO4 precipitates.</p>
<p>Good luck everyone! I’m off to attempt to sleep.</p>
<p>Thank you. It’s about 12:30 here, going to memorize solubility guidelines and memorize VSEPR, and then I’m going to sleep.</p>
<p>Good luck to everyone! Here’s hoping that the reactions’ll be as simple as last year’s (at least, simple relative to the past ones). Here’s hoping that the questions in the reaction section won’t ask me about precipitate colors (except for those of like, the common precipitates). Here’s hoping for an equilibrium problem on acids/bases, not solubility, or anything like that.</p>
<p>thank god im done! pretty easy overall!!</p>
<p>The test was a joke.</p>
<p>hate the eq problem</p>