Sodium stearate forms in water

Options

A. True solution
B. A suspension
C. An emulsion
D. A colloidal solution

Explanation

To determine what sodium stearate forms in water, let's break down the question step by step.

### Step 1: Identify Sodium Stearate
Sodium stearate is a sodium salt of stearic acid, which is a long-chain fatty acid. Its chemical formula is C18H35COONa.

### Step 2: Understand the Nature of Sodium Stearate
Sodium stearate is classified as a soap. Soaps are typically long-chain fatty acids that have been neutralized with sodium or potassium hydroxide. When dissolved in water, they can interact with water molecules due to their polar and non-polar regions.

### Step 3: Dissolution in Water
When sodium stearate is added to water, it dissociates into sodium ions (Na⁺) and stearate ions (C18H35COO⁻). The stearate ions have a long hydrophobic (water-repelling) tail and a hydrophilic (water-attracting) head.

### Step 4: Formation of Colloidal Solution
As sodium stearate dissolves, the hydrophobic tails of the stearate ions tend to aggregate together, while the hydrophilic heads remain in contact with water. This results in the formation of micelles, which are colloidal structures.

### Step 5: Conclusion
Since the particles of sodium stearate are dispersed in water and form a stable colloidal solution, we can conclude that sodium stearate forms a colloidal solution in water.

### Final Answer
Sodium stearate forms a colloidal solution in water.

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