How would you prepare tetraboric acid from boric acid ?

Explanation

To prepare tetraboric acid (H₂B₄O₇) from boric acid (H₃BO₃), follow these steps:

### Step 1: Heating Boric Acid
- Start with boric acid (H₃BO₃), which is a weak monobasic Lewis acid.
- Heat boric acid at around 170°C.

**Reaction:**
\[ \text{H}_3\text{BO}_3 \xrightarrow{\text{heat (170°C)}} \text{HBO}_2 + \text{H}_2\text{O} \]
...