Which of the following is not correct ?

Options

A. Lead is a true metal with +2 electrovalency
B. forms `PbCl_4` , which is soluble in organic solvent
C. Lead reacts with conc. HCl to form `PbCl_2` .
D. Lead reacts with NaOH solution to form `Pb(OH)_4`

Answer

To solve the question "Which of the following is not correct?" regarding the properties and reactions of lead (Pb), we will analyze each statement provided in the options step by step.

### Step 1: Analyze the first statement
**Statement:** Lead is a true metal with +2 electrovalency.

**Analysis:**
- Lead (Pb) is indeed a metal and can exhibit a +2 oxidation state.
- Electrovalency refers to the number of electrons an element can lose or gain.
- Lead can lose 2 electrons to achieve a stable configuration, confirming that this statement is **true**.

### Step 2: Analyze the second statement
**Statement:** Lead forms PbCl4 which is soluble in organic solvents.

**Analysis:**
- Lead can form PbCl4 (lead(IV) chloride), and it is known to be soluble in organic solvents.
- Additionally, PbCl4 acts as a strong oxidizing agent and can be hydrolyzed by water.
- Therefore, this statement is also **true**.

### Step 3: Analyze the third statement
**Statement:** Lead reacts with concentrated HCl to form PbCl2.

**Analysis:**
- When lead reacts with hydrochloric acid (HCl), it forms lead(II) chloride (PbCl2).
- This reaction is well-established in chemistry, confirming that this statement is **true**.

### Step 4: Analyze the fourth statement
**Statement:** Lead reacts with NaOH solution to form PbOH4.

**Analysis:**
- When lead reacts with sodium hydroxide (NaOH), it does not form PbOH4. Instead, it forms sodium plumbate, Na2PbO2.
- PbOH4 is not a stable compound formed in this reaction; it is a product of hydrolysis under different conditions.
- Therefore, this statement is **false**.

### Conclusion
After analyzing all the statements, we find that the fourth statement is not correct. Thus, the answer to the question is that the fourth statement is the one that is not correct.

### Final Answer
The statement that is not correct is: **Lead reacts with NaOH solution to form PbOH4.**

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