Tag: nitrogen and sulfur

Questions Related to nitrogen and sulfur

Assertion (A): In the synthesis of ammonia by Haber's process, mixture of potassium and aluminium oxides can be used as promoter.
Reason (R): Promoter enhances the activity of catalyst.

chemistry nitrogen and sulfur ammonia and fertilizers preparation of ammonia-laboratory method and haber's process ammonia

  1. Both (A) and (R) are true and (R) is the correct explanation of (A)

  2. Both (A) and (R) are true and (R) is not the correct explanation of (A)

  3. (A) is true and (R) is false

  4. (A) is false but (R) is true

Show answer
Correct Option: A
Explanation:

Promoter enhances the activity of catalyst (here iron), and because of which potassium and aluminium oxides are used as promoter in Haber's process.

Assertion (A): A mixture of $CaCN _2$ and graphite is known as nitration mixture.
Reason (R) : $NH _3$ is collected by downward displacement of air.

chemistry nitrogen and sulfur ammonia and fertilizers preparation of ammonia-laboratory method and haber's process ammonia

  1. Both (A) and (R) are true and (R) is the correct explanation of (A)

  2. Both (A) and (R) are true and (R) is not the correct explanation of (A)

  3. (A) is true and (R) is false

  4. (A) is false but (R) is true

Show answer
Correct Option: D
Explanation:

$HNO _{3}+H _{2}SO _{4}$ is known as nitration mixture. So, A is wrong.
$NH _{3}$ is collected by downward displacement of air as $NH _{3}$ is lighter than air.

The gas oxygen from thermal decomposition of $\displaystyle (NH _4) _2 \, Cr _2 O _7 $ :

chemistry nitrogen and sulfur ammonia and fertilizers preparation of ammonia-laboratory method and haber's process ammonia

  1. Oxygen

  2. Nitric oxide

  3. Ammonia

  4. Nitrogen

Show answer
Correct Option: D
Explanation:

$\displaystyle (NH _4) _2 \, Cr _2O _7 \, \overset{\Delta}{\longrightarrow} Cr _2O _3 + N _2 + 4H _2O $

In Haber process of  Ammonia production the element used as catalytic promoter to increase the activity of Iron catalyst is .......................

chemistry nitrogen and sulfur ammonia and fertilizers preparation of ammonia-laboratory method and haber's process ammonia

  1. NI (Nickel)

  2. W (Tungston)

  3. V (Vanadium)

  4. Mo (Molybednum)

Show answer
Correct Option: D
Explanation:

In Haber process of  ammonia production the element used as catalytic promoter to increase the activity of Iron catalyst is Mo (Molybednum).
$N _2+3H _2  \rightleftharpoons 2NH _3 + 24 \quad kcal$
The temperature is $450^oC$ and  the pressure is 200-250 atm.

The wrong statements about $\displaystyle NH _{3}$ is :

chemistry nitrogen and sulfur ammonia and fertilizers preparation of ammonia-laboratory method and haber's process ammonia

  1. it is oxidised with oxygen at $\displaystyle 700^{\circ}C$ in the presence of platinum

  2. it gives black precipitate with calomel

  3. it can be dried by $\displaystyle P _{2}O _{5},\ H _{2}SO _{4}\, $and$\, CaCl _{2}$

  4. it gives white fumes with HCI

Show answer
Correct Option: C
Explanation:
$NH _3$ is oxidised to nitric oxide and water with oxygen at $700^oC $ in the presence of platinum.
Aqueous ammonia reacts with calomel $Hg _2Cl _2$ to produce metallic mercury, a black precipitate. 
$CaO$ calcium oxide is used for drying of ammonia. Because $CaO$ being basic in nature does not react with $NH _3$ while $P _2O _5, $ conc. $H _2SO _4 \ $and$ \ CaCl _2$ reacts with it.
$CaO + H _2O + NH _3 \rightarrow NH _3 + Ca(OH) _2$
$CaCl _2 + 8NH _3 \rightarrow CaCl _2.8NH _3$
$P _2O _5 + 3H _2O + 6NH _3 \rightarrow 2(NH _4) _3PO _4$
$H _2SO _4 + NH _3 \rightarrow (NH _4) _2SO _4$
$NH _3$ gives White fumes of $NH _4Cl$ with $HCl$.
Nitrogen reacts with a metal $M$ to produce a compound $X$. This compound $X$ when dissolved in water forms pungent gas $Y$ which can be identified easily by the formation of white fumes in the presence of $HCl$.

Identify Y:
chemistry nitrogen and sulfur ammonia and fertilizers preparation of ammonia-laboratory method and haber's process ammonia

  1. Nitrogen dioxide

  2. Ammonia

  3. Nitrous oxide

  4. Nitric oxide

Show answer
Correct Option: B
Explanation:
$ 3Ca+{ N } _{ 2 }\xrightarrow [ \Delta  ]{  } { Ca } _{ 3 }{ N } _{ 2 } $

$ { Ca } _{ 3 }{ N } _{ 2 }+6{ H } _{ 2 }O\xrightarrow [  ]{  } 3Ca{ (OH) } _{ 2 }+2N{ H } _{ 3 } $
From the reaction we can see that the metal $ M $ is $Ca$ and pungent gas $ Y $ is Ammonia. 

Cyanamide process is used in formation of-

chemistry nitrogen and sulfur ammonia and fertilizers preparation of ammonia-laboratory method and haber's process ammonia

  1. $N _2$

  2. $HNO _3$

  3. $NH _3$

  4. $PH _3$

Show answer
Correct Option: C
Explanation:

Cyanamide process is a nitrogen fixation process in which Calcium Carbide and nitrogen react with each other at a high temperature to form Calcium Cyanamide.
The following reaction takes place:

$CaC _2$ $+$ $N _2$ $ \longrightarrow $ $CaCN _2$ $+$ $C$
At high temperature Calcium Cyanamide react with steam as follows:
$CaCN _2$ $+$ $3H _2O$ $\longrightarrow $ $CaCO _3$ $+$ $2NH _3$
Hence, $NH _3$ is formed.

In the Haber process for the industrial manufacturing of ammonia involving the reaction
${ N } _{ 2 }(g)+3{ H } _{ 2 }(g)\rightleftharpoons 2{ NH } _{ 3 }(g)$ at $200atm$ pressure in the presence of a catalyst, a temperature of about ${ 500 }^{ o }C$ is used. This is considered as optimum temperature for the process because:

chemistry nitrogen and sulfur ammonia and fertilizers preparation of ammonia-laboratory method and haber's process ammonia

  1. yield is maximum at this temperature

  2. catalyst is active only at this temperature

  3. energy needed for the reaction is easily obtained at this temperature

  4. rate of the catalytic reaction is fast enough while the yield is also appreciable for this exothermic reaction at this temperature

Show answer
Correct Option: A
Explanation:

In order to yield the maximum yield of ammonia, the temperature is lowered though $500^oC$ is not a low temperature. This temperature $(500^oC)$ is a compromise temperature to produce reasonably a high proportion of ammonia in the equilibrium mixture in a very short time.

Which of the following catalyst is used in the Haber process for the manufacture of ammonia?

chemistry nitrogen and sulfur ammonia and fertilizers preparation of ammonia-laboratory method and haber's process ammonia

  1. Platinized asbestos

  2. Iron with a suitable promoter

  3. Copper oxide

  4. Alumina

Show answer
Correct Option: B
Explanation:

The Haber process, also called the Haber Bosch process, is the industrial implementation of the reaction of nitrogen gas and hydrogen gas. It is the main industrial procedure to produce ammonia and catalyst used is iron with a suitable  promoter like $K _2O$, $CaO$, $SiO _2$, and $Al _2O _3$.
Option B is correct.

Ammonia gas is not prepared by :

chemistry nitrogen and sulfur ammonia and fertilizers preparation of ammonia-laboratory method and haber's process ammonia

  1. reduction of sodium nitrite or sodium nitrate by the reaction of zinc dust and sodium hydroxide

  2. hydrolysis of calcium cyanamide

  3. heating ammonium chloride with slaked lime

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

Show answer
Correct Option: D
Explanation:

(A) $NO _2^-+7[H]^-\xrightarrow {Zn/NaOH} NH _3+2H _2O; NO _3^-+9[H]^-\xrightarrow {Zn/NaOH} NH _3+3H _2O$
(B) $CaCN _2+3H _2O\rightarrow CaCO _3+2NH _3$
(C) $NH _4Cl+Ca(OH) _2\rightarrow 2NH _3+CaCl _2+2H _2O$
(D) $(NH _4) _2Cr _2O _7\rightarrow N _2+Cr _2O _3+4H _2O$