Question

Which of the following statements about $Na_2O_2$ is not correct?

• A. It is diamagnetic in nature.
• B. It is a derivative of $H_2O_2$
• C. $Na_2O_2$ oxidises $Cr^{3+}$ to $CrO_4^{2-}$ in acid medium.
• D. It is the super oxide of sodium.

Answer 1

The Correct Option is D

To determine which statement about Na_2O_2 is not correct, we need to evaluate each option based on the chemical properties and behavior of Na_2O_2 (Sodium Peroxide).

1. It is diamagnetic in nature.
   Na_2O_2 is composed of sodium and peroxide ions. The peroxide ion has paired electrons, making sodium peroxide diamagnetic. Hence, this statement is correct.
2. It is a derivative of H_2O_2.
   Sodium peroxide can be thought of as a derivative of hydrogen peroxide where the hydrogen atoms are replaced with sodium ions. Thus, this statement is correct.
3. Na_2O_2 oxidises Cr^{3+} to CrO_4^{2-} in acid medium.
   Na_2O_2 is a strong oxidizer. It can oxidize Cr^{3+} to CrO_4^{2-} in an acidic medium. Thus, this statement is correct.
4. It is the super oxide of sodium.
   The formula Na_2O_2 represents sodium peroxide, not a superoxide. The superoxide of sodium is NaO_2. Therefore, this statement is incorrect.

The correct answer is that Na_2O_2 is not the superoxide of sodium, but rather it is sodium peroxide. Thus, the correct answer is: "It is the super oxide of sodium."