An aqueous solution of Borax is:

Question

Accepted Answer

An aqueous solution of Borax is alkaline. Here's a detailed explanation supporting why Option 3 is correct and why the other options are incorrect:

1. **Explanation for Option 3 (Alkaline):**
   - Borax, chemically known as sodium borate (Na2B4O7·10H2O), is a salt of a weak acid (boric acid) and a strong base (sodium hydroxide). When dissolved in water, borax undergoes hydrolysis, which results in the formation of hydroxide ions (OH⁻). This increase in hydroxide ions makes the solution alkaline.
   - The chemical reaction can be represented as:
     $$
     \text{Na}_2\text{B}_4\text{O}_7 + 7\text{H}_2\text{O} \rightarrow 2\text{NaOH} + 4\text{H}_3\text{BO}_3
     $$
   - The presence of NaOH, a strong base, in the solution contributes to its alkaline nature, resulting in a pH greater than 7.

2. **Explanation for why other options are incorrect:**

- **Option 1 (Neutral):**
     - A neutral solution has a pH of 7. Since borax solution has a pH greater than 7 due to the presence of hydroxide ions, it cannot be neutral. Therefore, Option 1 is incorrect.

- **Option 2 (Amphoteric):**
     - An amphoteric substance can act as both an acid and a base. While borax itself is not amphoteric, it is a salt that results in an alkaline solution when dissolved in water. The solution does not exhibit amphoteric behavior; it is distinctly basic. Hence, Option 2 is incorrect.

- **Option 4 (Acidic):**
     - An acidic solution has a pH less than 7. Since the hydrolysis of borax produces hydroxide ions, which increase the pH above 7, the solution is not acidic. Therefore, Option 4 is incorrect.

In conclusion, the correct answer is Option 3, as an aqueous solution of borax is indeed alkaline due to the formation of hydroxide ions during hydrolysis.