Chemistry - Complete P-block Question with Solution | TestHub

Since the silicate contain 3 repeating ${\mathrm{SiO}}_3^{2-}$ units, it can have either of the following structures.

(A) In structure (A) only 2 oxygen atoms are shared so the silicate anion must be ${\mathrm{Si}}_3{\mathrm{O}}_{10}^{8-}$. In structure (B) 3 oxygen atoms are shared having the formula ${\mathrm{Si}}_3{\mathrm{O}}_9^{6-}$. If we consider the structure (B), the ${\mathrm{Ca}}^{2+}$ and ${\mathrm{Cu}}^{2+}$ cannot be in the ratio either $1:2$ or $2:1$. If structure $(A)$ is considered to neutralize 8 negative charges there must be 8 positive charges. This can be satisfied by taking $2C{a}^{2+}$ and $2C{u}^{2+}$ ions which are 1:1 ratio. Thus by counting the number of charges we can decide whether the silicate is chain or cyclic. Structure A contain total 10 oxygen atoms while structure (B) contain only 9 oxygen atoms. Thus by counting number charges, number of oxygen atoms shared and the total number of oxygen atoms in the given silicate, it can be decided whether it is cyclic or chain silicate.