Which of the following statements is not correct?

Options

A. a base is a compound which contains either oxide or hydroxide ions
B. `NH_3` when dissolved in water, forms an alkaline solution
C. a base is an electron acceptor
D. an aqueous solution of a base feels soapy to touch

Explanation

To determine which statement is not correct regarding acids, bases, and salts, we will analyze each statement one by one.

### Step 1: Analyze the First Statement
**Statement**: A base is a compound which contains either oxide or hydroxide ion.

**Analysis**: This statement is generally correct because many bases do contain oxide (O²⁻) or hydroxide (OH⁻) ions. However, it is important to note that not all bases necessarily contain these ions. For example, ammonia (NH₃) is a base but does not contain oxide or hydroxide ions. Therefore, while the statement is mostly true, it is not universally applicable.

### Step 2: Analyze the Second Statement
**Statement**: NH₃ when dissolved in water forms an alkaline solution.

**Analysis**: This statement is correct. When ammonia (NH₃) dissolves in water, it reacts to form ammonium hydroxide (NH₄OH), which is indeed alkaline in nature. Thus, this statement is true.

### Step 3: Analyze the Third Statement
**Statement**: An electron base is an electron acceptor.

**Analysis**: This statement is incorrect. According to the Lewis definition of acids and bases, bases are electron donors, not acceptors. For example, ammonia can donate a lone pair of electrons, making it a base. Therefore, this statement is not correct.

### Step 4: Analyze the Fourth Statement
**Statement**: An aqueous solution of base feels soapy to touch.

**Analysis**: This statement is correct. Aqueous solutions of bases often feel slippery or soapy due to the saponification reaction that occurs with fats and oils. Thus, this statement is true.

### Conclusion
After analyzing all the statements, we find that the third statement is the only one that is not correct. Therefore, the answer to the question is:

**Correct Answer**: The third statement is not correct.

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