Which of the following is the best imbibant ?

Options

A. Agar-Agar
B. Protein
C. Cellulose
D. Starch

Answer

**Step-by-Step Solution:**

1. **Understanding Imbibants**: Imbibants are solid substances that have the ability to absorb water. When these solids absorb water, the water is referred to as the imbibate.

2. **Defining Imbibation**: The process by which a solid absorbs water is called imbibation. This process generates a pressure within the solid, known as imbibational pressure.

3. **Identifying the Options**: The question presents several substances as options for the best imbibant. These include agar-agar, protein, cellulose, and starch.

4. **Analyzing Agar-Agar**: Agar-agar is a gel-like substance derived from red algae (seaweeds), specifically from species like Gracilaria and Gelidium. It is commercially available in powdered form and forms a jelly-like consistency when mixed with water.

5. **Comparing Other Options**: While protein, cellulose, and starch can absorb water, they do not exhibit the same level of gel formation and absorption capacity as agar-agar. Agar-agar is known for its superior ability to absorb water and form a stable gel.

6. **Conclusion**: Based on the properties of the substances listed, agar-agar is identified as the best imbibant among the options provided.

**Final Answer**: Agar-agar is the best imbibant.

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