Nature of Oxides

Q.

The compound which could not act both as oxidising as well as reducing agent is

1. MnO₂

2. SO₂

3. Al₂0₃

4. CrO

Q. Suboxides are a class of oxides wherein the electropositive element is in excess relative to the “normal” oxides - True or False?

1. True
2. False

Q. Calculate the oxidation number of iodine in KI3

Q. Amphoteric oxides are those which react with both acids and bases - True or False?

1. True
2. False

Q. Oxidation state of oxygen in Super oxides is:

1. $\frac{+1}{2}$
2. $\frac{-1}{2}$
3. $+1$
4. $Alloftheabove$

Q.

The formation of the oxide ion, $O_{\left(g\right)}^{2-}$ from oxygen atom requires first an exothermic and then an endothermic step as shown below:
$O_{\left(g\right)}+e^{-}\to O_{\left(g\right)}^{-};{\Delta }_f{H}^{\circ }=-141kJmo{l}^{-1}{O}_{\left(g\right)}^{-}+e^{-}\to O_{\left(g\right)}^{2-};{\Delta }_f{H}^{\circ }=+780kJmo{l}^{-1}$
Thus, process of formation of $O^{2-}$ in gas phase is unfavourable even though $O^{2-}$ is isoelectronic with neon. It is due to the fact that,

1. $O^{-}$ ion has comparatively smaller size than oxygen atom.

2. oxygen is more electronegative

3. addition of electron in oxygen results in larger size of the ion.

4. electron repulsion outweighs the stability gained by achieving noble gas configuration.

Q. Which of the following is true for Super oxides?

1. Chemical formula of anion is $O_2^{-}$
2. They are also called hyperoxide
3. Both (A) and (B)
4. None of these

Q. Which of the following is the anion corresponding to Super oxides?

1. $O_2^{-}$
2. $O^{-}$
3. $O_3^{-}$
4. All of the above

Q.

Metallic nature and basic nature of the oxides ........ as we move along a period

1. Remains constant

2. Decreases

3. First increases then decreases

4. Increases

Q. Which of the following is the anion corresponding to Super oxides?

1. $O_2^{-}$
2. $O^{-}$
3. $O_3^{-}$
4. All of the above

Q. Oxides which combine with water to form acids are called __ oxides.

Q. A highly reactive element (X) reacts with oxygen of air even at room temperature to give an oxide (Y). The oxide (Y) is soluble in water. The aqueous solution of (Y) does not change color of red litmus solution but reacts with an aqueous solution of sodium hydroxide. The $\left(X\right)$ is:

1. Sodium
2. Phosporous
3. Carbon
4. Sulphur

Q.

in the above ruels to ditermine the oxidation No. the second point states

• The oxidation number of a monoatomic ion is equal to the charge of the ion. For example, Mg²⁺ has oxidation number +2; Cl⁻ has oxidation number −1.

  here Mg²⁺ is not a monoatomic ion ?