Which of the following statements are false about soaps and detergents ?
(i) Soaps are water soluble while detergents are not.
(ii) Soaps are non-biodegradable while detergents are biodegradable.
(iii) Hardness of water is due to presence of `Ca` and `Mg` salts which form scum with soap.
(iv) The polar group in soaps is `-COONa`.

Options

A. (i), (ii) and (iii) only
B. (i) and (ii) only
C. (iii) and (iv) only
D. (i), (ii) and (iv) only

Explanation

To determine which statements about soaps and detergents are false, we will analyze each statement one by one.

### Step 1: Analyze Statement (i)
**Statement (i):** Soaps are water soluble while detergents are not.

- **Analysis:** Both soaps and detergents are water-soluble. Soaps dissolve in water, and detergents are specifically designed to be soluble in water as well. Therefore, this statement is **false**.

### Step 2: Analyze Statement (ii)
**Statement (ii):** Soaps are non-biodegradable while detergents are biodegradable.

- **Analysis:** Soaps are generally biodegradable because they are made from natural fats and oils. Detergents, particularly synthetic ones, are often non-biodegradable. Hence, this statement is also **false**.

### Step 3: Analyze Statement (iii)
**Statement (iii):** Hardness of water is due to the presence of Ca and Mg salts which form scum with soap.

- **Analysis:** This statement is true. Hard water contains calcium (Ca) and magnesium (Mg) ions, which react with soap to form an insoluble substance known as scum. Therefore, this statement is **true**.

### Step 4: Analyze Statement (iv)
**Statement (iv):** The polar group in soaps is -COONa.

- **Analysis:** The polar part of soap is indeed the sodium salt of fatty acids, which can be represented as -COONa. Therefore, this statement is **true**.

### Conclusion
The false statements are:
- Statement (i): Soaps are water soluble while detergents are not.
- Statement (ii): Soaps are non-biodegradable while detergents are biodegradable.

### Final Answer
The false statements about soaps and detergents are (i) and (ii).

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