Red and white phosphorus will differ but not in:

Options

A. smell
B. solubility in `CHCl_(3)`
C. exhibiting phosphorescence
D. reaction with concentrated `HNO_(3)`

Answer

To solve the question "Red and white phosphorus will differ but not in:", we need to analyze the differences and similarities between red phosphorus and white phosphorus across the provided options.

### Step-by-Step Solution:

1. **Understand the Properties of Phosphorus:**
- Red phosphorus and white phosphorus are two allotropes of phosphorus, and they have distinct physical and chemical properties.

2. **Analyze the Options:**
- **Option A: Smell**
- White phosphorus has a characteristic garlic-like odor, while red phosphorus is odorless.
- **Conclusion:** They differ in smell.

- **Option B: Solubility in CHCl3 (Chloroform)**
- White phosphorus is soluble in chloroform, while red phosphorus is not soluble in chloroform.
- **Conclusion:** They differ in solubility.

- **Option C: Exhibiting Phosphorescence**
- White phosphorus exhibits phosphorescence (it glows in the dark), whereas red phosphorus does not exhibit this property.
- **Conclusion:** They differ in exhibiting phosphorescence.

- **Option D: Reaction with Concentrated HNO3 (Nitric Acid)**
- Both red and white phosphorus react with concentrated nitric acid to produce similar products (phosphoric acid).
- **Conclusion:** They do not differ in this aspect.

3. **Final Answer:**
- The correct option is **D: Reaction with concentrated HNO3**. Red and white phosphorus will differ but not in their reaction with concentrated nitric acid.