<p>How do you approach a problem like this?</p>
<p>Hydrogen iodide gas is bubbled into a solution of lithium carbonate.</p>
<p>There were two possible solutions given:
HI + (CO3)2- --> I- + CO2 + H2O or
HI + (CO3)2- --> I + (HCO3)-
(not balanced)</p>
<p>The first of the two is correct. H2CO3 will always decompose to CO2 and H20 in water.</p>
<p>While Yoshi is correct, the 2004 answer key actually says they accepted either answer.</p>
<p>also, an acid + an oxyanion produces an oxide + water like this:</p>
<p>H+ + NO3- --> H2O + NO2</p>
<p>I might have to check up on that, but I'm pretty sure that's a general rule.</p>
<p>Wrong way around. A nonmetal oxide, when bubbled through water, produces an acid. Combining H+ with an anion doesn't automatically revert to the nometal oxide.
Ex
SO3 + H2O --> H+ + HSO4- (H2SO4 in its dissociated form)
But H+ + (SO4)2- does not turn into H2O plus SO3.</p>
<p>piccolojunior, but there's no acid-- it's HI gas. Does HI always behave like an acid?</p>
<p>well, HI is a strong acid...my rule is true but it might not be the explanation for the case given by the OP, since H2CO3 does dissociate into H2O and CO2</p>
<p>any other general rules for writing equations?</p>
<p>The HI was bubbled through a water solution, that's why it can act as an acid</p>
<p>Piccolo - your rule implies that</p>
<p>HCl(aq) + NaNO3(aq) --> H2O + NO2 + NaCl (not net ionic)</p>
<p>Which is absolutely <em>not</em> true.
HCl(aq) + NaNO3(aq) --> no reaction</p>
<p>No gfaith, a transition metal place in solution with a strong oxoacid does what I described. My fault lol.</p>
<p>Muchlove - that's too broad a question to answer.</p>
<p>The five basic reaction types (single replacement, double replacement, synthesis, decomposition, organic combustion) plus "water reactions", funky lewis acid/base reactions, redox (beyond simple single replacements) and complex ions covers most reactions that typically show up.
Of course, knowing solubility rules is a must.</p>