In permutit process, what is the role of the addition of the concentrated solution of the solid compound obtained due to the reaction between NaOH with HCl? Explain.

Explanation

### Step-by-Step Solution:

1. **Understanding the Permutit Process**:
The permutit process is a method used for softening hard water. Hard water contains high concentrations of calcium (Ca²⁺) and magnesium (Mg²⁺) ions, which can cause scaling and other issues in plumbing and appliances.

2. **Role of Sodium Permutit**:
Sodium permutit, which is chemically represented as Na2Al2SiO8·xH2O, is the key compound used in this process. When hard water is treated with sodium permutit, the calcium and magnesium ions in the hard water are exchanged with sodium ions from the sodium permutit.

...