Which of the following are incorrect statements ?

Options

A. `BH_(3)` is a stabel compound
B. Boron hydrides are readily hydrolysed
C. Boron hydrides are formed by the reation of `Mg_(3)B_(2)` and dil `HCl`.
D. All `B-H` bonds in `B_(2)H_(6)` are equal.

Explanation

To determine which statements are incorrect regarding boron compounds, let's analyze each statement step by step.

### Step 1: Analyze the first statement
**Statement:** "BH3 is a stable compound."

**Analysis:**
- Boron trihydride (BH3) is known to be a Lewis acid and is not stable in the free state. It tends to dimerize to form diborane (B2H6). Therefore, this statement is **incorrect**.

### Step 2: Analyze the second statement
**Statement:** "Boron hydrides are readily hydrolyzed."

**Analysis:**
- Boron hydrides, such as diborane (B2H6), do react with water, but the reaction is not straightforward and can be slow under certain conditions. Therefore, while they can hydrolyze, they are not described as "readily hydrolyzed." This statement is **incorrect**.

### Step 3: Analyze the third statement
**Statement:** "Boron hydrides are formed by the reaction of Mg3B2 and dilute HCl."

**Analysis:**
- This statement is correct. Boron hydrides can indeed be synthesized from the reaction of magnesium boride (Mg3B2) with dilute hydrochloric acid (HCl). Therefore, this statement is **correct**.

### Step 4: Analyze the fourth statement
**Statement:** "All BH bond distances in B2H6 are equal."

**Analysis:**
- In diborane (B2H6), there are two types of bonds: terminal BH bonds and bridge BH bonds. The terminal BH bond length is approximately 1.19 Å, while the bridge BH bond length is about 1.33 Å. Since these lengths are not equal, this statement is **incorrect**.

### Conclusion
Based on the analysis:
- The incorrect statements are:
1. "BH3 is a stable compound."
2. "Boron hydrides are readily hydrolyzed."
3. "All BH bond distances in B2H6 are equal."

Thus, the answer to the question is that the incorrect statements are the first, second, and fourth statements.