In the Zeolite (Permutit) process for softening hard water, the active material exchanges its sodium — Hydrogen Chemistry Question

💡 Solution & Explanation

Permutit or zeolite is chemically a hydrated sodium aluminium silicate, typically represented as $Na_2Al_2Si_2O_8 \cdot xH_2O$ or $Na_2Z$. It exchanges its $Na^+$ ions with the $Ca^{2+}$ and $Mg^{2+}$ ions responsible for water hardness.