With which of the following captions , alizarin will impart a rose red colour on the fibric

Options

A. `Fe^(3+)`
B. `Cr^(3+)`
C. `Ba^(+2)`
D. `Al^(+3)`

Answer

To determine which caption alizarin will impart a rose red color on the fabric, we need to understand the properties of alizarin and its interaction with fabrics.

### Step-by-Step Solution:

1. **Identify Alizarin**:
- Alizarin is a natural dye with the chemical formula C14H8O4. It is derived from the roots of the madder plant and is known for its ability to impart a red color to textiles.

**Hint**: Remember that alizarin is a natural dye obtained from a specific plant.

2. **Understanding the Structure**:
- Alizarin has a complex structure that includes benzene rings and functional groups (like hydroxyl groups). This structure is crucial for its dyeing properties.

**Hint**: Focus on the functional groups in the structure of alizarin that may interact with fabrics.

3. **Fabric Composition**:
- The primary component of many fabrics, such as cotton, is cellulose. For alizarin to effectively dye the fabric, it must bond with the cellulose.

**Hint**: Consider the material composition of the fabric when thinking about dyeing processes.

4. **Role of Mordants**:
- Mordants are substances that help fix the dye to the fabric. They create a bond between the dye and the fabric. In the case of alizarin, aluminum ions (Al³⁺) are commonly used as mordants.

**Hint**: Recall that mordants are essential for the dyeing process, as they enhance the bonding of the dye to the fabric.

5. **Conclusion**:
- Since aluminum ions are used as mordants to bind alizarin to the cellulose in fabrics, the correct caption that alizarin will impart a rose red color on the fabric is associated with aluminum.

**Final Answer**: The answer is option number 4, which refers to aluminum as the mordant used with alizarin to achieve the rose red color on fabric.