How to recognize Barium sulphite?
Sulphite$(\ce{SO3^2-})$ and Barium Choride$(\ce{ BaCl2})$ or Strontium Chloride$(\ce{ SrCl2})$:
$$\ce{SO3^2- +Ba^2+ -&gt;BaSO3 v}$$
the precipate disoolves in dilute hydrochloric acid, when sulphur dioxide evolves:
$$\ce{BaSO3 v +2H+ -&gt;Ba^2+ +SO2 ^ +H2O}$$
On standing, the precipitate is slowly oxidises to the sulphate and is then insoluble in dilute mineral acids; this change is rapidly effected by warming with bromine water or a little concentrated nitric acid or with hydrogen peroxide:
$$\ce{2BaSO3 v +O2 -&gt;2BaSO4 v }\\
\ce{2BaSO3 v +Br2 + H2O-&gt;BaSO4 v +2Br- +2H+}\\
\ce{2BaSO3 v +2HNO3 -&gt;3BaSO4 v +2NO ^ +H2O}\\
\ce{2BaSO3 v +H2O2 -&gt;BaSO4 v +H2O}$$
The solubilites at $\pu{18 ^\circ C}$ of the sulphites of $\ce{Ca,Sr,Ba}$ are respectively $1.25, 0.033, 0.022$ all in $\pu{g/l}$
Source:

Vogel’s Qualitative Inorganic Analysis for the JEE, by Svehla/Sivasankar,  7/e Paperback, 1 January 2013