Pick out the incorrect statement about CO .

Options

A. In laboratory it is prepared by dehydrating HCOOH with conc. `H_2SO_4`
B. CO is neutral oxide and acts as a fuel
C. It reduces aqueous solution of `PdCl_2` to metallic Pd
D. Co forms complex with haemoglobin and this complex is less stable than oxyhaemoglobin

Answer

To determine the incorrect statement about carbon monoxide (CO), we will analyze each of the provided statements step by step.

### Step 1: Analyze the first statement
**Statement:** In the laboratory, CO can be prepared by dehydrating formic acid (HCOOH) with H2SO4.

- **Explanation:** This statement is true. When formic acid is treated with sulfuric acid (H2SO4), which acts as a dehydrating agent, water is removed, leading to the formation of carbon monoxide (CO) and other byproducts.

### Step 2: Analyze the second statement
**Statement:** Cu is a neutral oxide.

- **Explanation:** This statement is also true. Copper (Cu) can be considered a neutral oxide because it does not react with acids or bases in a significant manner, and it can be used in various applications, including as a fuel in certain contexts.

### Step 3: Analyze the third statement
**Statement:** CO can reduce the aqueous solution of PdCl2 to metallic Pd.

- **Explanation:** This statement is true as well. Carbon monoxide (CO) is a strong reducing agent and can reduce palladium(II) chloride (PdCl2) in an aqueous solution to metallic palladium (Pd), producing carbon dioxide (CO2) and hydrochloric acid (HCl) as byproducts.

### Step 4: Analyze the fourth statement
**Statement:** Cu forms a complex with hemoglobin and this complex is less stable than oxyhemoglobin.

- **Explanation:** This statement is incorrect. Hemoglobin contains iron (Fe) as its metal center, not copper (Cu). While CO can bind to hemoglobin, forming carboxyhemoglobin, this statement incorrectly attributes the formation of a complex to copper. The stability of the CO-hemoglobin complex is actually greater than that of oxyhemoglobin, making this statement false.

### Conclusion
The incorrect statement about CO is the fourth one: "Cu forms a complex with hemoglobin and this complex is less stable than oxyhemoglobin."

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