Which of the following is//are incorrect statement(s) for phosphine ?

Options

A. It is less basic then `NH_(3)`.
B. It is less poisonous then `NH_(3)`.
C. The solution of `PH_(3)` in water does not decompose.
D. Phosphine on heating at `150^(circ)C` "burns forming" `H_(3)PO_(4)`.

Explanation

To determine which statements about phosphine (PH₃) are incorrect, let's analyze each statement step by step.

### Step 1: Analyze Statement A
**Statement A:** "It is less basic than ammonia."

- **Explanation:** Ammonia (NH₃) is known to be more basic than phosphine. This is primarily due to the higher electronegativity of nitrogen compared to phosphorus. The lone pair of electrons on nitrogen in ammonia is more available for donation than the lone pair on phosphorus in phosphine. Therefore, this statement is **correct**.

### Step 2: Analyze Statement B
**Statement B:** "It is less poisonous than ammonia."

- **Explanation:** Phosphine is actually more poisonous than ammonia. Ammonia has a pungent smell but is less toxic compared to phosphine, which is highly toxic and can be lethal in small concentrations. Thus, this statement is **incorrect**.

### Step 3: Analyze Statement C
**Statement C:** "The solution of PH₃ in water does not decompose."

- **Explanation:** When phosphine is dissolved in water, it does decompose. The reaction of phosphine with water produces red phosphorus and liberates hydrogen and oxygen gases. Therefore, this statement is also **incorrect**.

### Step 4: Analyze Statement D
**Statement D:** "Phosphine on heating at 150 degrees Celsius burns forming H₃PO₄."

- **Explanation:** When phosphine is heated in the presence of oxygen, it combusts and forms phosphoric acid (H₃PO₄). Therefore, this statement is **correct**.

### Conclusion
Based on the analysis:
- **Correct Statements:** A and D
- **Incorrect Statements:** B and C

### Final Answer
The incorrect statements for phosphine are B and C.

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