give one method of preparation of `Na_(2)B_(4)O_(7)`

Explanation

To prepare sodium tetraborate (Na₂B₄O₇), commonly known as borax, we can follow this method:

### Step-by-Step Preparation:

1. **Starting Materials**: Gather the necessary reactants: boric acid (H₃BO₃) and sodium carbonate (Na₂CO₃).

2. **Reaction Setup**: In a suitable reaction vessel, combine boric acid and sodium carbonate in the appropriate stoichiometric amounts.

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