Calcium and magnesium salts are present in hard water when reacts with calgon [ Na 2 [ Na 4 ( PO 3 ) 6 ] ] it gives complex salt 'X' and 'Y' . X & Y are -

Question

Calcium and magnesium salts are present in hard water when reacts with calgon [ Na 2 ​ [ Na 4 ​ ( PO 3 ​ ) 6 ​ ] ] it gives complex salt 'X' and 'Y' . X & Y are -

TestHub · Accepted Answer

Correct Option: The correct answer is (B). \

Calgon Structure: Calgon is sodium hexametaphosphate, which is written in complex form as $N a_{2} [N a_{4} (P O_{3})_{6}]$ .

Ion Exchange Principle: When added to hard water, the $C a^{2 +}$ and $M g^{2 +}$ ions displace the four $N a^{+}$ ions present inside the coordination sphere.

Calcium Complex (X): The reaction with calcium ions yields $N a_{2} [C a_{2} (P O_{3})_{6}]$ along with displaced sodium ions:

$N a_{2} [N a_{4} (P O_{3})_{6}] + 2 C a^{2 +} \to N a_{2} [C a_{2} (P O_{3})_{6}] + 4 N a^{+}$

Magnesium Complex (Y): Similarly, the reaction with magnesium ions yields the soluble complex $N a_{2} [M g_{2} (P O_{3})_{6}]$ :

$N a_{2} [N a_{4} (P O_{3})_{6}] + 2 M g^{2 +} \to N a_{2} [M g_{2} (P O_{3})_{6}] + 4 N a^{+}$

Chemistry - Complete s-block Question with Solution | TestHub

Options:

Doubts & Discussion