H2O2 + NaCl + H(+) reaction? So I found these reduction potentials online:

$$\begin{alignat}{2}
\ce{H2O2 + 2H+ + 2e- \;&amp;&lt;=&gt; 2H2O}\qquad &amp;&amp;E=1.78\ \mathrm V\\
\ce{2Cl- \;&amp;&lt;=&gt; Cl2 + 2e-}\qquad &amp;&amp;E=-1.36\ \mathrm V
\end{alignat}$$

If the net reduction potential is positive will chlorine gas be spontaneously formed when salt and hydrogen peroxide are mixed in a acidic solution?
Not necessarily.  If you get the pH right and the stoichiometry absolutetly 1:1 then you might form $\ce{Cl2}$.  However your reaction will compete with other reaction and you will more likely oxidize the chlorine into chlorate ions ($\ce{ClO-}$, $\ce{ ClO2-}$, $\ce{ClO3-}$, or $\ce{ClO4-}$).