Which of the following is incorrect

Options

A. Red P is toxic
B. White 'P' is highly soluble in `CS_(2)`
C. Black 'P' is thermadynamic is most stable.
D. White 'P' is soluble in NaOH evolves `PH_(3)`

Answer

To solve the question "Which of the following is incorrect?" regarding the properties of different allotropes of phosphorus, we will analyze each option step by step.

### Step 1: Analyze Option A
**Statement:** Red Phosphorus is toxic.
**Analysis:** Red phosphorus is generally considered non-toxic. In contrast, white phosphorus is known to be highly toxic. Therefore, this statement is incorrect.

### Step 2: Analyze Option B
**Statement:** White Phosphorus is highly soluble in Carbon Disulfide.
**Analysis:** White phosphorus is indeed soluble in carbon disulfide (CS2) but is insoluble in water. This statement is correct.

### Step 3: Analyze Option C
**Statement:** Black Phosphorus is thermodynamically most stable.
**Analysis:** Black phosphorus is the most stable allotrope of phosphorus under standard conditions. It does not ignite in air up to about 673 Kelvin, making this statement correct.

### Step 4: Analyze Option D
**Statement:** White Phosphorus is soluble in NaOH, evolves pH 3.
**Analysis:** White phosphorus reacts with sodium hydroxide (NaOH) and water to produce phosphine gas and sodium hypophosphite. This reaction does indeed occur, and the solution can have a pH around 3. Thus, this statement is also correct.

### Conclusion
After analyzing all the options:
- Option A is the only incorrect statement. Therefore, the answer is **Option A**.

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