Finding moles of water evolved How many moles of water are released on gentle heating of 1 mole of $\ce{Al2Cl6•12H2O}$?

Since the heating is gentle, the water molecules that are not present in inner orbital complex of compound and not directly attached to aluminium will be evolved, but the structure of $\ce{Al2Cl6}$ is a bridged tetrahedron. Then again, water is a better ligand than chlorine, so overall I cannot decide what the structure of the compound should be.
Anhydrous aluminium chloride ($\ce{AlCl3}$) exists; however, it cannot be obtained by heating of the hexahydrate ($\ce{AlCl3.6H2O}$).

$$\ce{AlCl3.6H2O \rlap{\ \ \not}-&gt;[\quad] AlCl3 + 6 H2O}$$

The crystalline hexahydrate $\ce{AlCl3.6H2O}$ actually is the complex salt $\ce{[Al(H2O)6]^3+ 3 Cl-}$.

The acidic hexaaquaaluminium(3+) ion is susceptible to hydrolysis.

$$\ce{[Al(H2O)6]^3+ &lt;=&gt; Al(OH)3 + 3 H3O+}$$

Therefore, the hexahydrate $\ce{AlCl3.6H2O}$ hydrolyses upon gentle heating and releases three equivalents of water and hydrogen chloride.

$$\ce{AlCl3.6H2O -&gt; Al(OH)3 + 3 HCl + 3 H2O}$$