When zeolite, which is hydrated sodium aluminium silicate, is treated with hard water the sodium ions are exchanged with 1 . H + ions 2 . C a 2 + ions 3 . S O 4 - 2 ions 4 . M g 2 + ions

Step-by-step solution

N a 2 A l 2 S i 2 O 8 . x H 2 O (zeolite) is written as N a 2 Z . In it N a + ions exchange C a + and M g 2 + ions of hard water to remove permanent hardness of water as follows N a 2 Z + M g 2 + → 2 N a + + M g Z N a 2 Z + C a 2 + → 2 N a + + C a Z