Which statements is/ are correct.

Options

A. When `FeCl_(3)` is added to excess of hot water, a positvely charged colloidal solution form.
B. Amount of electrolyte required to cause coagulation is higher for lyophobie than lyophillie colloide
C. High pressure is favaourable for physical as well as chemical adsorption
D. Physical and chemical adsorption both decrease entropy of universe

Answer

To determine which statements are correct, let's analyze each statement one by one.

### Step 1: Analyze Statement 1
**Statement:** When FeCl3 is added to excess of hot water, a positively charged colloidal solution is formed.

**Analysis:** When FeCl3 is dissolved in water, it hydrolyzes to form hydrated iron oxides, which can create a positively charged colloidal solution. Therefore, this statement is **correct**.

### Step 2: Analyze Statement 2
**Statement:** The amount of electrolyte required to cause coagulation is higher for lyophobic than for lyophilic colloids.

**Analysis:** This statement is **incorrect**. Lyophilic colloids require less electrolyte for coagulation compared to lyophobic colloids. Lyophobic colloids are more stable and require a higher concentration of electrolyte to cause coagulation.

### Step 3: Analyze Statement 3
**Statement:** High pressure is favorable for physical as well as chemical adsorption.

**Analysis:** This statement is **correct**. High pressure increases the amount of gas that can be adsorbed on a surface, making it favorable for both physical and chemical adsorption processes.

### Step 4: Analyze Statement 4
**Statement:** Physical and chemical adsorption both decrease the entropy of the universe.

**Analysis:** This statement is **correct**. When a gas is adsorbed onto a surface, the randomness (or entropy) of the system decreases because the gas molecules become more ordered when they adhere to the surface.

### Conclusion
Based on the analysis:
- Statement 1: Correct
- Statement 2: Incorrect
- Statement 3: Correct
- Statement 4: Correct

Thus, the correct statements are A (Statement 1), C (Statement 3), and D (Statement 4). Statement B is incorrect.

### Final Answer
The correct statements are A, C, and D.

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