Tag: chemistry

Questions Related to chemistry

Which of the following when dissolved in water will liberate ammonia ?

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

  1. ${Na NO _3}$

  2. ${Na NO _2}$

  3. ${Na NH _2}$

  4. ${Na _3N}$

Show answer
Correct Option: C,D
Explanation:

Reactions:
$Na _3N+ 3H _2O \rightarrow 3NaOH + NH _3$
$H _2O+NaNO _3\rightarrow H _2O+NaOH+NO$
$NaNH _2+H _2O(hot) \rightarrow NaOH + NH _3$
$NaNO _2 + H _2O \rightarrow HNO _2 + NaOH$

Industrially, ammonia is obtained by direct combination between nitrogen and hydrogen. The formation of ammonia is promoted at:

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

  1. 1000 atm

  2. 200 atm

  3. 25 atm

  4. 1 atm

Show answer
Correct Option: B
Explanation:

Ammonia is prepared industrially by Haber's process.

In this process, dinitrogen directly reacts with Dihydrogen in $1:3$ in presence of iron catalyst with promoters as oxides of potassium or aluminium.
The physical conditions required for this process are $200-300$ atm pressure and $400-450^0C$ temperature.

How is ammonia collected?

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

  1. Ammonia is less dense than air so it is collected by upward delivery.

  2. Ammonia is more dense than air so it is collected by upward delivery.

  3. Ammonia is more dense than air so it is collected by downward delivery.

  4. None of the above.

Show answer
Correct Option: A
Explanation:

Ammonia is less dense than air so it is collected by upward delivery or gas syringe method.
In upward delivery method a gas jar is connected by a tube to flask that is giving off gas. The gas that is less dense than air rises to the top of gas jar. The air in the gas jar is displaced until the gas jar is filled with collected gas. Ammonia is very soluble gas so the collection apparatus should be dry and not collected over water.

Write the balanced equation for the preparation of $NH _3$ from ammonium chloride and calcium hydroxide.

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

  1. ${ 4NH } _{ 4 }Cl+Ca\left( OH \right) _{ 2 }\rightarrow 2{ NH } _{ 3 }+2{ CaCl } _{ 2 }+{ 2H } _{ 2 }O$

  2. ${ 2NH } _{ 4 }Cl+2Ca\left( OH \right) _{ 2 }\rightarrow 2{ NH } _{ 3 }+2{ CaCl } _{ 2 }+{ 2H } _{ 2 }O$

  3. ${ 2NH } _{ 4 }Cl+Ca\left( OH \right) _{ 2 }\rightarrow 2{ NH } _{ 3 }+{ CaCl } _{ 2 }+{ 2H } _{ 2 }O$

  4. ${ NH } _{ 4 }Cl+Ca\left( OH \right) _{ 2 }\rightarrow { NH } _{ 3 }+{ CaCl } _{ 2 }+{ 2H } _{ 2 }O$

Show answer
Correct Option: C
Explanation:

${ 2NH } _{ 4 }Cl+Ca\left( OH \right) _{ 2 }\rightarrow 2{ NH } _{ 3 }+{ CaCl } _{ 2 }+{ 2H } _{ 2 }O$

Warming ammonium sulphate with sodium hydroxide solution gives :

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

  1. ammonia

  2. chlorine

  3. nitrogen

  4. none of these

Show answer
Correct Option: A
Explanation:

$(NH _4) _2SO _4 + 2NaOH \rightarrow Na _2SO _4 + 2H _2O + 2NH _3$

Heating ammonium chloride with sodium hydroxide produces :

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

  1. ammonia

  2. nitrogen

  3. chlorine

  4. none of these

Show answer
Correct Option: A
Explanation:

$NH _4Cl + NaOH \rightarrow H _2O + NH _3 + NaCl $

Which reaction of ammonia forms the first step of Ostwald's process?

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

  1. The catalytic oxidation of ammonia by platinum catalyst

  2. The catalytic oxidation of ammonia by cobalt catalyst

  3. The catalytic reduction of ammonia by platinum catalyst

  4. The oxidation of ammonia

Show answer
Correct Option: A
Explanation:

The first step of Ostwald's process is the catalytic oxidation of ammonia by platinum catalyst for the formation of nitric acid.

$NH _3+O _2 \xrightarrow {Pt} NO+ H _2O$

$N _2(g) + 3H _2(g)\overset{Fe+Mo}{\rightleftharpoons}2NH _3(g)$; Haber's process.

Mo is used as :

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

  1. a catalyst

  2. a catalytic promoter

  3. an oxidising agent

  4. a catalytic poison

Show answer
Correct Option: B
Explanation:

$NH _3$ is manufactured by Haber's process.
$N _2(g) + 3H _2(g)\overset{Fe+Mb}{\rightleftharpoons}2NH _3(g)$
In this process, pure nitrogen and hydrogen gases react in the ratio of $1:3$ by volume in $400^0C-500^0C$ temperature, $200-900$ atm pressure in presence of iron as catalyst and Mo as promoter.

A mixture of $NH _4Cl$ and $NaCl$ can be separated by

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

  1. filtration

  2. Distillation

  3. Sublimation

  4. Decantation

Show answer
Correct Option: C
Explanation:

$NH _4$ undergoes sublimation while NaCI does not.

 In commercial industry, ammonia is prepared by :

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

  1. decomposition of salts

  2. contact process

  3. arc process

  4. combining  hydrogen and nitrogen gases (Haber process)

Show answer
Correct Option: D
Explanation:

 In commercial industry, ammonia is prepared by combining hydrogen and nitrogen gases (Haber process).
$N _2 + 3H _2 \rightleftharpoons 2NH _3+24\ kcal$