Q: The most abundant element in earth's crust is:

The most abundant element in earth's crust is oxygen with\$\text{ Percent by weight = 46.1% followed by aluminium with 8.23% by weight.}\$Hence, the answer is option \$B\$.

Q: Why is \$KO_{2}\$ paramagnetic ?

\$KO_2\$ is a superoxide which containd odd number of electrons (unpaired electron). Therefore KO2 is paramagnetic in nature.

Q: The following reaction is used for the preparation of oxygen gas in the laboratory.\$2KClO_{3} (s) \xrightarrow[Catalyst]{Heat} 2KCl (s) + 3O_{2} (g)\$Which of the following statement is correct about the reaction?

\$2KClO_{3}(s) \xrightarrow[catalyst]{heat} 2KCl(s) + 3O_{2}(g)\$In the above reaction, potassium chlorate(\$KClO_{3}\$) decomposes to form potassium chloride(KCl) and oxygen(\$O_{2}\$). Also as shown in the equation, heat is supplied for the reaction to take place. Therefore, it is a decomposition reaction which is also endothermic in nature.

Q: Which of the following does not react with oxygen directly?\$Zn, Ti, Pt, Fe\$

\$Pt\$ is a noble metal and does not react very easily. All other elements, \$Zn,\ Ti,\ Fe\$ are quite reactive. Hence, oxygen does not react with platinum (\$Pt\$) directly.

Q: How is oxygen prepared from the following compound?\$PbO_2\$

Oxygen prepared by following reactions\$PbO_{2(s)}\rightarrow PbO_{(s)}+\dfrac{1}{2}O_{2(g)}\$.

Q: Explain the formation of (i) water gas(ii) producer gas. Give their uses.

(i) A mixture of carbon monoxide (\$CO\$) and hydrogen (\$H_2\$) produced by passing steam over red-hot coke .\$C(s) + H_2O(g) \overset{473-1273K}{\rightarrow} CO(g) + H_2(g)\$ (water gas)(ii) A combustible mixture of nitrogen, carbon monoxide, and hydrogen, generated by passing air with steam over burning coke or coal in a furnace and used as fuel\$ 2C(s) + O_2(g) + 4N_2(g) \overset{1273K}{\rightarrow} 2CO(g) + 4N_2(g)\$ (producer gas)Water gas and producer gas are used as fuel

Q: Which of the following liberates \$O_2\$ upon hydrolysis?

(A) \$Pb_3O_4+H_2O\rightarrow \$ No reaction(B) \$2KO_2+2H_2O\rightarrow 2KOH +H_2O_2+O_2\$(C) \$Na_2O_2+2H_2O\rightarrow 2NaOH + H_2O_2\$(D) \$Li_2O_2+2H_2O\rightarrow 2LiOH + H_2O_2\$So, option B is the correct answer.

Question 1

The most abundant element in earth's crust is:

Accepted Answer

The most abundant element in earth's crust is oxygen with$\text{ Percent by weight = 46.1% followed by aluminium with 8.23% by weight.}$Hence, the answer is option $B$.

Question 2

Explain why $O_2$ molecule is paramagnetic in nature ?

Accepted Answer

We can explain the paramagnetic nature of oxygen molecule by molecular orbital theory.When you draw molecular orbital diagram of $O_2$we can see there are two unpaired electrons are present in the last molecular orbital which shows us that it is paramagnetic in nature.

Question 3

Why is $KO_{2}$ paramagnetic ?

Accepted Answer

$KO_2$ is a superoxide which containd odd number of electrons (unpaired electron). Therefore KO2 is paramagnetic in nature.

Question 4

The following reaction is used for the preparation of oxygen gas in the laboratory.
$2 K C l O_{3} (s) H e a t C a t a l y s t 2 K C l (s) + 3 O_{2} (g)$
Which of the following statement is correct about the reaction?

Accepted Answer

$2KClO_{3}(s)  \xrightarrow[catalyst]{heat}  2KCl(s)  +  3O_{2}(g)$In the above reaction, potassium chlorate($KClO_{3}$) decomposes to form potassium chloride(KCl) and oxygen($O_{2}$). Also as shown in the equation, heat is supplied for the reaction to take place. Therefore, it is a decomposition reaction which is also endothermic in nature.

Question 5

A solution of sodium sulphate in water is electrolysed using inert electrodes. The products at the cathode and anode are respectively:

Accepted Answer

A solution of sodium sulphate in water is electrolysed using inert electrodes. The products at the cathode and anode are ${H_2}$, ${O_2}$ respectively.Hydrogen ions having lower discharge (or higher reduction) potential than sodium ions will be liberated at the cathode.$\displaystyle 2H^+ + 2e^- \rightarrow H_2 \uparrow$Hydroxide ions having a lower discharge potential than sulphate ions, will be liberated at anode.$\displaystyle 4OH^- \rightarrow 2H_2O + O_2 + 4e^-$

Question 6

Answer the following questions:1. Explain interhalogen compounds.2. How is oxygen prepared from the following compound?   $KClO_4$

Accepted Answer

Interhalogen compounds:Interhalogen compounds are the compounds which contains two or more different halogen atoms and no other elements from any other group.Some of the interhalogen compounds are $ClF, ClF_3, IF_5, IF_7$Generally larger atom combines with other halogens having smaller atomic size.Oxygen prepared by following reaction.$KClO_{4(s)}\rightarrow KCl_{(s)}+2O_{2(g)}$.

Question 7

Which of the following does not react with oxygen directly?$Zn, Ti, Pt, Fe$

Accepted Answer

$Pt$ is a noble metal and does not react very easily. All other elements, $Zn,\ Ti,\ Fe$ are quite reactive. Hence, oxygen does not react with platinum ($Pt$) directly.

Question 8

How is oxygen prepared from the following compound?$PbO_2$

Accepted Answer

Oxygen prepared by following reactions$PbO_{2(s)}\rightarrow PbO_{(s)}+\dfrac{1}{2}O_{2(g)}$.

Question 9

Explain the formation of (i) water gas(ii) producer gas. Give their uses.

Accepted Answer

(i) A mixture of carbon monoxide ($CO$) and hydrogen ($H_2$) produced by passing steam over red-hot coke .$C(s) + H_2O(g) \overset{473-1273K}{\rightarrow} CO(g) + H_2(g)$ (water gas)(ii) A combustible mixture of nitrogen, carbon monoxide, and hydrogen, generated by passing air with steam over burning coke or coal in a furnace and used as fuel$ 2C(s) + O_2(g) + 4N_2(g) \overset{1273K}{\rightarrow} 2CO(g) + 4N_2(g)$ (producer gas)Water gas and producer gas are used as fuel

Question 10

Which of the following liberates $O_2$ upon hydrolysis?

Accepted Answer

(A) $Pb_3O_4+H_2O\rightarrow $ No reaction(B) $2KO_2+2H_2O\rightarrow 2KOH +H_2O_2+O_2$(C) $Na_2O_2+2H_2O\rightarrow 2NaOH + H_2O_2$(D) $Li_2O_2+2H_2O\rightarrow 2LiOH + H_2O_2$So, option B is the correct answer.

Preparation of Dioxygen

Language

Rate

REVISE WITH CONCEPTS

Preparation of Oxygen

QUICK SUMMARY WITH STORIES

Preparation of Oxygen

The most abundant element in earth's crust is:

Explain why $O_{2}$ molecule is paramagnetic in nature ?

Why is $K O_{2}$ paramagnetic ?

The following reaction is used for the preparation of oxygen gas in the laboratory.
$2 K C l O_{3} (s) H e a t C a t a l y s t 2 K C l (s) + 3 O_{2} (g)$
Which of the following statement is correct about the reaction?

A solution of sodium sulphate in water is electrolysed using inert electrodes. The products at the cathode and anode are respectively:

Answer the following questions:

1. Explain interhalogen compounds.

2. How is oxygen prepared from the following compound?
$K C l O_{4}$

Which of the following does not react with oxygen directly?
$Z n, T i, P t, F e$

How is oxygen prepared from the following compound?

$P b O_{2}$

Explain the formation of
(i) water gas
(ii) producer gas. Give their uses.

Which of the following liberates $O_{2}$ upon hydrolysis?

Preparation of Dioxygen

Language

Rate

REVISE WITH CONCEPTS

Preparation of Oxygen

QUICK SUMMARY WITH STORIES

Preparation of Oxygen

The most abundant element in earth's crust is:

Explain why O2​ molecule is paramagnetic in nature ?

Why is KO2​ paramagnetic ?

The following reaction is used for the preparation of oxygen gas in the laboratory. 2KClO3​(s)HeatCatalyst​2KCl(s)+3O2​(g) Which of the following statement is correct about the reaction?

A solution of sodium sulphate in water is electrolysed using inert electrodes. The products at the cathode and anode are respectively:

Answer the following questions: 1. Explain interhalogen compounds. 2. How is oxygen prepared from the following compound? KClO4​

Which of the following does not react with oxygen directly? Zn,Ti,Pt,Fe

How is oxygen prepared from the following compound? PbO2​

Explain the formation of (i) water gas (ii) producer gas. Give their uses.

Which of the following liberates O2​ upon hydrolysis?

Explain why $O_{2}$ molecule is paramagnetic in nature ?

Why is $K O_{2}$ paramagnetic ?

The following reaction is used for the preparation of oxygen gas in the laboratory.
$2 K C l O_{3} (s) H e a t C a t a l y s t 2 K C l (s) + 3 O_{2} (g)$
Which of the following statement is correct about the reaction?

Answer the following questions:

1. Explain interhalogen compounds.

2. How is oxygen prepared from the following compound?
$K C l O_{4}$

Which of the following does not react with oxygen directly?
$Z n, T i, P t, F e$

How is oxygen prepared from the following compound?

$P b O_{2}$

Explain the formation of
(i) water gas
(ii) producer gas. Give their uses.

Which of the following liberates $O_{2}$ upon hydrolysis?