<p>I'm having a bit of trouble with some review questions for AP Chem. If someone could help me I'd appriciate it. <a href="http://physicsforums.com/showthread.php?t=170167%5B/url%5D">http://physicsforums.com/showthread.php?t=170167</a> is where I posted the questions(as this board doesn't support LaTeX formatting).</p>
<p>Thanks in advance!</p>
<p>i think that #1 is 4H+ + 1S-2 + 2NO3-1 -----> 2NO2 + 1S8 + 2H2O
plain old redox balacing if im not mistaken</p>
<p>But then where would the eight sulfer atoms that are present on the right come from, as there is only one on the left side.</p>
<p>Also, what about the rest of the questions?</p>
<p>use Ag(NO3) Mg(NO3)2 as the electrolytes. u don't want Ag+ to precipitate.
And in 2e) just do 3.18-0.0592/2*log[(0.002)/0.1^2]</p>
<h1>3) Assuming your math is correct (I didn't check) if the current is sufficient to move 0.75 mol of e-, but only 0.25 mol of metal is reduced at the cathode, then there must be 3mol e-/mol metal, therefore oxidation state is +3</h1>
<p>What about the electrolyte for the salt bridge? I remember when we did a similar experiment we dipped the salt bridge in some solution. What solution would be ideal for dipping the salt bridge in?</p>
<p>
[quote]
use Ag(NO3) Mg(NO3)2 as the electrolytes. u don't want Ag+ to precipitate.
[/quote]
</p>
<p>Ag(NO3) and Mg(NO3)2</p>
<p>^^ no, silver nitrate and magnesium nitrate would be the solutions in the separate beakers. For the salt bridge, you need an inert salt, one that can pass into the beaker solutions without contaminating the reaction. Potassium nitrate is often used. (Potassium is too hard to reduce to interfere.)</p>
<h1>1: your answer looks right to me, considering you're balancing in acid.</h1>
<p>gfaith: What is another possible salt bridge electrolyte?</p>
<p>oops，thanks for the correction, gfaith ^_^</p>
<p>@mikesown, it could be KCl too</p>