Question

1. What is permuitit? How is it useful in removing permanent hardness of water? 

2. Compare the structures of water and hydrogen peroxide.

Answer 1

1. Hydrated sodium aluminium silicate is called permutit (NaZ). When it is added to hard water it exchanges Ca²⁺ and Mg²⁺ ions with Na⁺ ions. 

2NaZ(s) + M²⁺(aq) —> MZ₂(s) + 2Na⁺ (aq) M = Ma, Ca) 

2. Water molecule has an angular or bent shape. H₂O₂ has a non-planar structure.