AHHH chem question again!

<p>A 22.0 g sample of Iron is dissolved into concentrated hydrochloric acid (sp. gravity a.k.a. density 1.18 and 35.0% by mass HCl) How many milliliters of the hydrochloric acid would be necessary to dissolve the iron?</p>

<p>The answer is 69.7 mL but I can't get it...</p>

<p>good question! i don't get their answer, either. assuming your density is in grams per mL and we're talking about iron (II) [using iron (III) gets an answer that seems way off], here's what i get.</p>

<p>Fe + HCl --> FeCl2 + H2</p>

<p>22 / 55.847 = .3939 mol Fe
.3939 * 2/1 = .7879 mol Cl
.7889 * 35.4527 = 27.93 g Cl
27.93 / .35 = 79.81 g solution
79.81 /1.18 = 67.6 mL</p>

<p>an answer about 3% off. is that what you got? i don't know what to say =&lt;/p>

<p>You forgot to add the two hydrogens, but if you do, the answer, which is 69.5 is still not like the book's answer</p>

<p>Yeah, I got about what you somethingsmellsfunny, only a hundredth off or so I believe. </p>

<p>Thanks for the help, guys</p>