Stoichiometric reaction of hydrochloric acid, potassium nitrate, and copper I have the following reaction involving these elements:


$\ce{HCl}$ (hydrochloric acid)
$\ce{KNO3}$ (potassium nitrate, a nitrate salt)
$\ce{Cu}$ (copper)


The reaction should produce nitrogen dioxide ($\ce{NO2}$).

The chemical equation should look like this:

$$
\ce{HCl + KNO3 + Cu -&gt; NO2}
$$

But I'm clearly missing something. Can anybody help me equalize and complete this equation?
My apologizes, I found the answer. The full equation is :
$$\ce{Cu + 4KNO3 + 4HCl -&gt; Cu(NO3)2 + 2NO2 + 4KCl + 2H2O}$$
(I'll detail this later)