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Source: Concise Chemistry-ICSE (Class X)SELINA PUBLISHERS Pg 207

In this book, it is mentioned that ferrous sulfite and aluminum sulfite does not exist. I even tried searching these on Google but didn't get any satisfactory results.

Why do these compounds do not exist?enter image description here

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  • $\begingroup$ Uploaded the page which you can't find $\endgroup$ – Swastik May 18 '17 at 10:28
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    $\begingroup$ Why Aluminum sulphite is rare?Does it have to do with Fajan's Rule?My guess is aluminum cation have so high charge dense that it makes the compound aluminum sulphite to spontaneously degrade to yield aluminum oxide and sulphur dioxide. @Berry Holmes $\endgroup$ – Swastik May 18 '17 at 14:29
  • $\begingroup$ Can you add that part to your answer? @Nilay Ghosh $\endgroup$ – Swastik May 19 '17 at 3:34
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Iron sulfite does exist. This site describe the properties of the compound.

Ferrous sulfite, $\ce{FeSO3.3H2O}$, is obtained by dissolving iron in aqueous sulfurous acid in the absence of air. Upon concentration the salt is deposited as colourless crystals. The reaction is somewhat complicated, for no hydrogen gas is liberated during the solution of the iron, the nascent hydrogen reducing some of the sulfurous acid (or ferrous sulfite) to thiosulfuric acid (or ferrous thiosulfate). Thus:

$$\ce{2Fe + 3H2SO3 -> FeSO3 + FeS2O3 + 3H2O}$$

The thiosulfate, being very soluble in water, remains in solution.

Ferrous sulfite also results when solutions of ferrous salts and sodium sulfite interact, and when ferrous hydroxide is dissolved in aqueous sulfurous acid. In these circumstances a red solution is usually obtained, probably because of interaction with dissolved oxygen. The colour quickly disappears, however, particularly on warming. On concentration, the salt crystallises out.

On passing a current of sulfur dioxide into an aqueous suspension of freshly precipitated ferrous sulfide, the latter passes into solution and ferrous sulfite is gradually deposited:

$$\ce{FeS + SO2 + H2O -> FeSO3 + H2S}$$

Ferrous sulfite solution readily oxidises in air, yielding a red solution. From its colourless solutions alkalies precipitate ferrous hydroxide.

Aluminum sulfite is poorly known. Only one line is written about it in the same site.

Various basic salts have been described. The acid sulfite solution has been used for purifying beet sugar

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    $\begingroup$ Why Aluminum sulfite is rare? @Nilay Ghosh $\endgroup$ – Swastik May 17 '17 at 18:20

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