Question

Which of the following statements is correct?

• A. Zeolites have a more closed structure than feldspar.
• B. $H _{4} As _{2} O _{7}$ is an 'ortho' acid.
• C. Pseudo-alum does not have $Na ^{+}$and $K ^{+}$.
• D. Superphosphate of lime is $4 Ca \left( H _{2} PO _{4}\right)_{2}$.

Answer 1

Answer: (C)

Pseudo-alum does not have $Na ^{+}$and $K ^{+}$.

Answer 2

Pseudo-alum constitute a class in which monovalent atom of true alum is replaced by a divalent atom. Hence, $Na ^{+}$and $K ^{+}$are not present in pseudo-alums. Further feldspar has a more closed structure, $H _{4} As _{2} O _{7}$ is a 'pyro' acid and superphosphate of lime is $Ca \left( H _{2} PO _{4}\right)_{2}+2 CaSO _{4}$.