Which of the following statement(s) is/are incorrect?

Options

A. Magnesium may by extracted by self reduction method
B. Down's Cell process is used to extract magnesium from sea water
C. Magnalium is an alloy of magnesium
D. Formula of Epsom salt is `MgSO_(4)*6H_(2)O`

Answer

To determine which statements are incorrect, we will analyze each statement one by one.

### Step 1: Analyze Statement 1
**Statement:** Magnesium may be extracted by self-reduction method.

**Analysis:**
- Magnesium cannot be extracted by the self-reduction method.
- The correct method for isolating magnesium is through the electrolysis of fused magnesium chloride, often in the presence of sodium chloride.

**Conclusion:** Statement 1 is incorrect.

### Step 2: Analyze Statement 2
**Statement:** Downe's cell process is used to extract magnesium from seawater.

**Analysis:**
- The Downe's cell process is actually used for the extraction of sodium, not magnesium.
- It involves the electrolysis of fused sodium chloride (NaCl) in the presence of calcium chloride and potassium chloride.

**Conclusion:** Statement 2 is incorrect.

### Step 3: Analyze Statement 3
**Statement:** Magnelium is an alloy of magnesium.

**Analysis:**
- Magnelium is indeed an alloy of magnesium, containing aluminum and small amounts of copper, nickel, and tin.

**Conclusion:** Statement 3 is correct.

### Step 4: Analyze Statement 4
**Statement:** The formula of Epsom salt is MgSO4.6H2O.

**Analysis:**
- The correct formula for Epsom salt is MgSO4.7H2O, which means it is a heptahydrate, not a hexahydrate as stated.

**Conclusion:** Statement 4 is incorrect.

### Final Conclusion:
The incorrect statements are:
- Statement 1: Incorrect
- Statement 2: Incorrect
- Statement 4: Incorrect

### Summary of Incorrect Statements:
1. Magnesium may be extracted by self-reduction method. (Incorrect)
2. Downe's cell process is used to extract magnesium from seawater. (Incorrect)
3. Magnelium is an alloy of magnesium. (Correct)
4. The formula of Epsom salt is MgSO4.6H2O. (Incorrect)