Tag: preparation of gases

Questions Related to preparation of gases

On heating a mixture of $NH _{4}Cl$ and $KNO _{2}$, we get:

chemistry preparation of gases nitrogen gas component of air - nitrogen nitrogen

  1. $NH _{4}NO _{3}$

  2. $KNH _{4}(NO _{3}) _{2}$

  3. $N _{2}$

  4. $NO$

Show answer
Correct Option: C
Explanation:

On heating mixture of $NH _4Cl$ and $KNO _2$, $N _2$ is obtained with potassium chloride and water.

$NH _4Cl+KNO _2\longrightarrow N _2+KCl+2H _2O$

On heating ammonium dichromate and barium azide separately we get:

chemistry preparation of gases nitrogen gas component of air - nitrogen nitrogen

  1. $N _{2}$ in both cases

  2. $N _{2}$ with ammonium dichromate and $NO$ with barium azide

  3. $N _{2}O$ with ammonium dichromate and $N _{2}$ with barium azide

  4. $N _{2}O$ with ammonium dichromate and $NO _{2}$ with barium azide

Show answer
Correct Option: A
Explanation:

On heating ammonium dichromate and barium azide separately we get $N _2$ in both cases.

$(NH _4) _2Cr _2O _7 \rightarrow Cr _2O _3 + 4H _2O +N _2$.

$Ba(N _3) _2 \rightarrow Ba + 3N _2$.

Hence option A is correct.

Concentrated nitric acid on reacting with any metal like copper releases gas with an irritating odour :

chemistry preparation of gases nitrogen gas component of air - nitrogen nitrogen

  1. $H _2 S$

  2. $CuS$

  3. $H _2$

  4. $NO _2$

Show answer
Correct Option: D
Explanation:

Nitrogen dioxide is the chemical compound with the formula $NO _2$. It is one of several nitrogen oxides. $NO _2$ is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year. This reddish-brown toxic gas has a characteristic sharp, biting odor and is a prominent air pollutant. Reduction of concentrated nitric acid by metal (such as copper).
$4 HNO _3 +Cu \rightarrow Cu(NO _3) _2+ 2 NO _2 + 2 H _2O$

Nitrogen is liberated by the thermal decomposition of :

chemistry preparation of gases nitrogen gas component of air - nitrogen nitrogen

  1. $NH _4NO _2$

  2. $NaN _3$

  3. $(NH _4) _2Cr _2O _7$

  4. All of these

Show answer
Correct Option: D
Explanation:

$ { { (NH } _{ 2 }) } _{ 2 }{ Cr } _{ 2 }{ O } _{ 7 }\xrightarrow [ thermal\quad decomposition ]{ \Delta  } { Cr } _{ 2 }{ O } _{ 3 }+{ N } _{ 2 }+4{ H } _{ 2 }O\ N{ H } _{ 4 }{ NO } _{ 2 }\xrightarrow [ thermal\quad decomposition ]{ \Delta  } { N } _{ 2 }+2{ H } _{ 2 }O\ 2{ NaN } _{ 3 }\xrightarrow [ thermal\quad decomposition ]{ \Delta  } 2Na+3{ N } _{ 2 } $

Hence, all of these. 

Out of the following which does not liberate $N _2$ gas on heating?

chemistry preparation of gases nitrogen gas component of air - nitrogen nitrogen

  1. $NaNO _2+NH _4Cl$

  2. $Ba(N _3) _2$

  3. $O _3+NO$

  4. $(NH _4) _2Cr _2O _7$

Show answer
Correct Option: C
Explanation:

A. $NaNO _2+NH _4Cl\longrightarrow N _2+2H _2O+NaCl$

B. $Ba(N _3) _2\longrightarrow Ba+3N _2$
C. $O _3+NO\longrightarrow NO _2+O _2$
D. $(NH _4) _2Cr _2O _7 \longrightarrow N _2+Cr _2O _3+4H _2O$
Hence, answer is $O _3+NO$..

Among the following compounds, which on heating do not produce ${ N } _{ 2 }$?

chemistry preparation of gases nitrogen gas component of air - nitrogen nitrogen

  1. ${ \left( { NH } _{ 4 } \right) } _{ 2 }{ Cr } _{ 2 }{ O } _{ 7 }$

  2. ${ NH } _{ 4 }CI+Na{ NO } _{ 2 }$

  3. ${ NH } _{ 4 }CI+CaO$

  4. $Ba{ \left( { N } _{ 3 } \right) } _{ 2 }$

Show answer
Correct Option: C
Explanation:

The reaction is given by,

$2 NH _4Cl + CaO → 2 NH _3 + CaCl _2 + H _2O$

20 ml of mixture of $N _{2}$ and $CH _{4}$ was exploded with excess of air. There is contraction of 5 ml in volume after treatment with KOH solution, what is the percentage of $N _{2}$ in the mixture?($N _{2}$ is inert)

chemistry preparation of gases nitrogen gas component of air - nitrogen nitrogen

  1. $25%$

  2. $50%$

  3. $87.5%$

  4. $80%$

Show answer
Correct Option: C

Which of the following compound does not liberate nitrogen with $HNO _{2}$?

chemistry preparation of gases nitrogen gas component of air - nitrogen nitrogen

  1. Carbamide

  2. Primary amine

  3. Secondary amine

  4. Alkanamide

Show answer
Correct Option: C
Explanation:

Secondary amines do not read with $HNO _2$ to produce $H _2.$

$\Rightarrow R _2NH+H-O-N=0\rightarrow R _2N-N=0+H _2O$
Hence, the answer is secondary amines.

Which of the following compounds does not give nitrogen on heating?

chemistry preparation of gases nitrogen gas component of air - nitrogen nitrogen

  1. $NaN _3$

  2. $(NH _4) _2SO _4$

  3. $NH _4NO _2$

  4. $(NH _4) _2Cr _2O _7$.

Show answer
Correct Option: B
Explanation:

(A) $2NaN _3\xrightarrow {\Delta} 2Na+2N _2$
(B) $(NH _4) _2SO _4\xrightarrow {\Delta} 2NH _3+H _2SO _4$
(C) $NH _4NO _2\xrightarrow {\Delta} N _2+2H _2O$
(D) $(NH _4) _2Cr _2O _7\rightarrow N _2+Cr _2O _3+4H _2O$

Which of the chemical(s) is/are related to Solvay process directly or indirectly?

chemistry preparation of gases nitrogen gas component of air - nitrogen nitrogen

  1. $K C l$

  2. $C O _ { 2 }$

  3. $N H _ { 3 }$

  4. $C a ( O H ) _ { 2 }$

Show answer
Correct Option: B,C