Which is not truw regarding silicones?

Options

A. `(CH_(3))_(2)SiCl_(2)` on hydrolysis in excess of water gives a linear chain silicone
B. `(CH_(3))_(2)SiCl_(2)` on hydrolysis in limited supply of water gives mainly six membered cyclic silicone
C. `(CH_(3))_(2)SiCl` is added during synthesis of silicone to control the molar mass
D. Silicones are all solid plastic at room temperature

Answer

To determine which statement is not true regarding silicones, we will analyze each of the provided statements one by one.

### Step 1: Analyze the First Statement
**Statement A**: "CS3 whole-toys SiCl2 on hydrolysis gives a linear chain of silicones."

- **Explanation**: The compound CS3 whole-toys SiCl2 is known as dichlorosilane. When it undergoes hydrolysis with excess water, it produces silanol (CS3 whole-toys SiOH) and releases HCl. Upon further condensation and polymerization of silanol, a linear chain of silicones is formed. Therefore, this statement is true.

### Step 2: Analyze the Second Statement
**Statement B**: "CS3 whole-toys CSICL is added during synthesis to control molar mass."

- **Explanation**: In the synthesis of silicones, the addition of CS3 whole-toys SiCl (methylchlorosilane) is indeed used to control the molar mass of the silicone product. This is done by terminating the polymer chain, thus preventing it from growing indefinitely. Therefore, this statement is also true.

### Step 3: Analyze the Third Statement
**Statement C**: "Silicones are solid plastic."

- **Explanation**: Silicones can exist in various forms, including liquids and rubber-like materials at room temperature. They are not exclusively solid plastics; rather, they can be flexible and are often used as lubricants and adhesives. Therefore, this statement is false.

### Conclusion
After analyzing all three statements, we conclude that the statement which is not true regarding silicones is:

**Answer**: Statement C: "Silicones are solid plastic."

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