Point out the incorrect one

Options

A. Hardness of water depends upon its soap consuming powerr
B. Temporary hardness is due to bicarbonate of calcium and magnesium
C. Permanent hardness is due to soluble sulphates, chlorides and nitrates of Ca and Mg
D. Permanent hardness can be removed by boiling water

Explanation

To solve the question of identifying the incorrect statement regarding the hardness of water, let's analyze each option step by step.

### Step 1: Understand Hardness of Water
Hardness of water is primarily due to the presence of calcium (Ca²⁺) and magnesium (Mg²⁺) ions. These ions affect the soap-consuming power of water, meaning the more hardness present, the more soap is needed to form lather.

**Hint:** Remember that hardness is related to the concentration of calcium and magnesium ions.

### Step 2: Analyze Option 1
**Statement:** Hardness of water depends upon its soap-consuming power.

This statement is **correct**. The presence of calcium and magnesium ions in water indeed affects how much soap is consumed. More hardness means more soap is needed to produce lather.

**Hint:** Think about how soap interacts with ions in water.

### Step 3: Analyze Option 2
**Statement:** Temporary hardness is due to the bicarbonate of calcium and magnesium.

This statement is also **correct**. Temporary hardness is caused by the presence of bicarbonates of calcium and magnesium, which can be removed by boiling.

**Hint:** Recall the difference between temporary and permanent hardness.

### Step 4: Analyze Option 3
**Statement:** Permanent hardness is due to soluble sulfates, chlorides, and nitrates of calcium and magnesium.

This statement is **correct**. Permanent hardness is indeed caused by these soluble salts, which do not precipitate upon boiling.

**Hint:** Consider what types of compounds contribute to permanent hardness.

### Step 5: Analyze Option 4
**Statement:** Permanent hardness can be removed by boiling water.

This statement is **incorrect**. Permanent hardness cannot be removed by boiling; it requires chemical treatment (like using a cleansing agent) to remove the hardness.

**Hint:** Remember the methods used to treat different types of hardness.

### Conclusion
After analyzing all the options, we find that the incorrect statement is:

**Correct Answer:** Option 4 - "Permanent hardness can be removed by boiling water."