Chemistry

Chemistry of Gases and Applications

1,175 Questions

The chemistry of gases covers atmospheric composition, noble gases, and various applications of gas compounds in industrial and biological processes. Understanding the properties of common gases, their reactions, and environmental occurrences is vital for general science sections. Use these questions to practice identifying gases and their specific uses.

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Chemistry of Gases and Applications Questions

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

Which of the following factors would favour the formation of ammonia?

  1. High pressure

  2. Low temperature

  3. High volume

  4. Low pressure
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
According to Le Chatelier's principle, high pressure would favour the formation of $NH _{3}$
$N _{2}$(g) + 3$H _2${g) $\leftrightharpoons$ $NH _{3}$(g)
The optimum conditions for the production of $NH _{3}$ are pressure of 200 x 10$^{5}$ Pa (about 200 atm) and temperature of -700 K.
In the given reaction, the number of moles of reactant is more than the product and according to the ideal gas equation, the pressure is inversely proportional to the number of moles.
Thus, by increasing pressure i.e. at high pressure, the reaction will proceed in a forward direction towards less number of moles. Thus the formation of the ammonia increases.
Multiple choice chemistry nitrogen and sulfur ammonia and fertilizers preparation of ammonia-laboratory method and haber's process ammonia

Ammonia is dried over :

  1. Quick lime

  2. Slaked lime

  3. Phosphorus pentoxide
  4. Con. $\mathrm{H} _{2}\mathrm{S}\mathrm{O} _{4}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Ammonia is dried by passing it over quick lime because it is a basic gas. Ammonia cannot be dried by conc. sulphuric acid or phosphorus pentaoxide as they will form ammonium sulphate or ammonium phosphate with it.

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

Ammonia can be collected by displacement of

  1. Water
  2. $Conc.{ H } _{ 2 }S{ O } _{ 4 }$

  3. Brine

  4. Mercury
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Ammonia is an extremely soluble gas and cannot be collected by displacement of water or acid. It can only be collected over a liquid in which it does not dissolve. 

One such liquid is mercury because it does not react with ammonia and it can be easily collected by displacement of the metal as it is liquid at room temperature. 

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

Two major requirements for preparation of ammonia are

  1. Low temperature and high pressure

  2. Low temperature and present pressure

  3. High temperature and low pressure

  4. High temperature and high pressure
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

This reaction is 

(a) reversible,

 (b) exothermic, and 

(c) proceeds with a decrease in volume.

According to the Le Chatelier's principle, the favorable conditions for the formation of ammonia are,

Low temperature

The temperature should be remain as low as possible, (although at unusually low temperatures, the rate of reaction becomes slow). It has been found that the temperature, which optimizes the yield of ammonia for the reaction, is maximum at about 500°C.

High pressure

Since Haber's process proceeds with a decrease in volume, it is favored by high pressure. In actual practice, a pressure of 200 - 900 atmospheres is employed.

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

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.

  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
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

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

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

  1. Platinized asbestos

  2. Iron with a suitable promoter

  3. Copper oxide

  4. Alumina
Reveal answer Fill a bubble to check yourself
B Correct answer
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.

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

Ammonia gas is not prepared by :

  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 $(NH _4) _2Cr _2O _7$
Reveal answer Fill a bubble to check yourself
D Correct answer
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) $(NH _4) _2Cr _2O _7\rightarrow N _2+Cr _2O _3+4H _2O$