Preparation and Properties of Potassium Peroxide and Superoxide

Q. The correct order of the number of unpaired electrons in the ions, ${\text{Cu}}^{2+},{\text{Ni}}^{2+},{\text{Fe}}^{3+}\text{and}{\text{Cr}}^{3+}$ is

1. ${\text{Fe}}^{3+}>{\text{Cr}}^{3+}>{\text{Ni}}^{2+}>{\text{Cu}}^{2+}$
2. ${\text{Fe}}^{3+}>{\text{Cr}}^{3+}>{\text{Cu}}^{2+}>{\text{Ni}}^{2+}$
3. ${\text{Cr}}^{3+}>{\text{Fe}}^{3+}>{\text{Ni}}^{2+}>{\text{Cu}}^{2+}$
4. ${\text{Cu}}^{2+}>{\text{Ni}}^{2+}>{\text{Cr}}^{3+}>{\text{Fe}}^{3+}$

Q. Which one of the following oxides is expected to exhibit paramagnetic behavior?

1. 
2. 
3. 
4. 

Q. Among the following the paramagnetic compound is

1. 
2. 
3. 
4. 

Q. $K{O}_2$ is used in oxygen cylinders in space and submarines because

1. It eliminates moisture
2. It eliminates $N_2$
3. It absorbs $C{O}_2$ and increases $O_2$ content
4. produces ozone

Q.

$K{O}_2$ finds use in breathing equipment to safeguard the user to breathe in oxygen generated internally in the apparatus without being exposed to toxic fumes outside. The supply of oxygen is due to :

i.Slow decomposition of $K{O}_2$

ii.reaction of superoxide with moisture in the exhaled air

iii.reaction of $K{O}_2$ with $C{O}_2$ in the exhaled air

1. only iii is correct
2. ii and iii are correct
3. both i and iii are correct
4. i ii and iii are all correct

Q.

$K{O}_2$ finds use in breathing equipment to safeguard the user to breathe in oxygen generated internally in the apparatus without being exposed to toxic fumes outside. The supply of oxygen is due to :

i.Slow decomposition of $K{O}_2$

ii.reaction of superoxide with moisture in the exhaled air

iii.reaction of $K{O}_2$ with $C{O}_2$ in the exhaled air

1. only iii is correct

2. ii and iii are correct

3. both i and iii are correct

4. i ii and iii are all correct

Q.

$K{O}_2$ (potassium superoxide) is used in oxygen cylinders in space and submarines because it:

1. absorbs CO₂

2. absorbs CO₂ and increases O₂ contents

3. eliminates moisture

4. produces ozone.

Q. Which of the following species is paramagnetic?

1. $C{O}_2$
2. $NO$
3. $O_2^{2-}$
4. $C{N}^{-}$

Q. Among halogens, the correct order of amount of energy released in electron gain (electron gain enthalpy) is:

1. $F>Cl>Br>I$
2. $F<Cl<Br<I$
3. $F<Cl>Br>I$
4. $F<Cl<Br<I$

Q. Among $K{O}_2,AI{O}_2^{-},Ba{O}_2$ and $N{O}_2^{+}$ unpaired electron is present in

1. 
2. 
3. only
4. only

Q.

Which one of the alkali metals, forms normal oxide $M_{2}O$ on heating in excess of air?

1. $Li$
2. $Cs$
3. $Rb$
4. $K$

Q. The correct order of increasing thermal stabilities of alkaline earth metal sulphates is:

1. $SrS{O}_4<CaS{O}_4<MgS{O}_4<BeS{O}_4$
2. $BeS{O}_4<MgS{O}_4<CaS{O}_4<SrS{O}_4$
3. $CaS{O}_4<BeS{O}_4<MgS{O}_4<SrS{O}_4$
4. $MgS{O}_4<BeS{O}_4<CaS{O}_4<SrS{O}_4$

Q. $K{O}_2$ (potassium superoxide) is used in oxygen cylinders in space and submarines because it

1. eliminates moisture
2. Produces ozone
   
   
3. absorbs and increases content
4. absorbs

Q. Match List I (Compounds) with List II (Associated Uses).

Q. $K{O}_2$ is used in oxygen cylinders in space and submarines because

1. It eliminates moisture

2. produces ozone

3. It eliminates N₂

4. It absorbs CO₂ and increases O₂ content

Q.

A paramagnetic solid, which might cause explosive reactions with some compounds, is used in rebreathers and such life-support systems to scrub $C{O}_2$ and to produce $O_2$ is:

1. 

2. 

3. 

4. 

Q. Sodium burns in excess air to give mainly:

1. $N{a}_{2}O$
2. $Na{O}_2$
3. $N{a}_2{O}_2$
4. $NaH$

Q. Which one of the following property is not shown by $NO$?

1. It combines with oxygen to form nitrogen dioxide.
2. It is diamagnetic in gaseous state.
3. It's bond order is $2.5$.
4. It is a neutral oxide.

Q. Assertion :$NO$ is diamagnetic in solid or liquid state but paramagnetic in gaseous state. Reason: $NO$ contains one unpaired electron.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Assertion is incorrect but Reason is correct

Q. $N_{2}O$ is paramagnetic in nature.
If true 1 else 0.

1. 0

Q. A substance which gives a brick red flame and breaks down on heating giving oxygen and a brown gas is :

1. calcium carbonate
2. magnesium carbonate
3. magnesium nitrate
4. calcium nitrate

Q. Draw the diagram showing mcelle formation by the

Q. How will you distinguish between?
Glucose and sucrose (cane-sugar).

Q. The correct order of stabilities of the following superoxides is

1. 

2. 

3. 

4. 

Q. If true enter 1, else enter 0.
If two compounds have the same crystal structure and analogous formula, they are named as isomorphous.

Q.

A paramagnetic solid, which might cause explosive reactions with some compounds, is used in rebreathers and such life-support systems to scrub $C{O}_2$ and to produce $O_2$ is:

1. $KN{O}_3$

2. $K_{2}S{O}_4$

3. $K_2{O}_2$

4. $K{O}_2$

Q. Oxide of nitrogen formed in the atmosphere during the lightenings is:

1. $NO$
2. $N_{2}O$
3. $N{O}_2$
4. $None$

Q. The heat of adsorption in case of physisorption is approximately $20$ - $40kJmo{l}^{-1}$.

1. 1

Q. Which of the compound is both paramagnetic and coloured ?

1. $Cu{F}_2$
2. $K_2\left[TiC{l}_6\right]$
3. $K_3\left[Cu\right(CN{)}_4]$
4. $K_{2}Cr{O}_4$

Q.

$K{O}_2$ finds use in breathing equipment to safeguard the user to breathe in oxygen generated internally in the apparatus without being exposed to toxic fumes outside. The supply of oxygen is due to :

i.Slow decomposition of $K{O}_2$

ii.reaction of superoxide with moisture in the exhaled air

iii.reaction of $K{O}_2$ with $C{O}_2$ in the exhaled air

1. only iii is correct
2. ii and iii are correct
3. both i and iii are correct
4. i ii and iii are all correct