Tag: chemistry

Questions Related to chemistry

Hydrogen gas is manufactured by:

chemistry study of the first element - hydrogen occurrence of hydrogen introduction to hydrogen hydrogen

  1. Bosch's process

  2. Haber's process

  3. Ostwald process

  4. Birkeland-Eyde process

Show answer
Correct Option: A
Explanation:

Among the given option, the Bosch process is correct.

It is the commercial preparation of dihydrogen from water gas.
$C+{ H } _{ 2 }O\longrightarrow CO+{ H } _{ 2 }$
$CO+{ H } _{ 2 }O \xrightarrow { 773K }  { CO } _{ 2 }+{ H } _{ 2 }O$

The process of producing syngas from coal is called ______________.

chemistry study of the first element - hydrogen occurrence of hydrogen introduction to hydrogen hydrogen

  1. coal cracking

  2. coal gasification

  3. coal pyrolysis

  4. both $A$ and $B$

Show answer
Correct Option: B
Explanation:

Coal gasification is the process of producing syngas–a mixture consisting primarily of methane ($C{ H } _{ 4 }$), carbon monoxide (CO), hydrogen (${ H } _{ 2 }$), carbon dioxide ($C{ O } _{ 2 }$) and water vapor (${ H } _{ 2 }O$)–from coal and water, air and/or oxygen.

Dihydrogen can be prepared on a commercial scale by different methods. In its preparation by the action of steam on hydrocarbons, a mixture of $CO$ and $H 2$ gas is formed. It is known as __________.

chemistry study of the first element - hydrogen occurrence of hydrogen introduction to hydrogen hydrogen

  1. water gas

  2. syngas

  3. producer gas

  4. industrial gas

Show answer
Correct Option: A,B
Explanation:

Steam reforming is a method for producing hydrogen, carbon monoxide, or other useful products from hydrocarbon fuels such as natural gas. This is achieved in a processing device called a reformer which reacts steam at high temperature with the fossil fuel.

Steam reforming of natural gas - sometimes referred to as steam methane reforming (SMR) - is the most common method of producing commercial bulk hydrogen. Hydrogen is used in the industrial synthesis of ammonia and other chemicals. At high temperatures (700 – 1100 °C) and in the presence of a metal-based catalyst (nickel), steam reacts with methane to yield carbon monoxide and hydrogen.

$C{ H } _{ 4 }+{ H } _{ 2 }O\leftrightharpoons CO+3{ H } _{ 2 }$

Following reaction is called __________ reaction.
$CO (g)\ +\ H _2O (g) \xrightarrow [catalyst]{673} CO _2(g)\ +\ H _2(g)$

chemistry study of the first element - hydrogen occurrence of hydrogen introduction to hydrogen hydrogen

  1. combustion

  2. disproportionate

  3. coal gasification

  4. water-gas shift

Show answer
Correct Option: D
Explanation:

The water-gas shift reaction (WGSR) describes the reaction of carbon monoxide and water vapor to form carbon dioxide and hydrogen (the mixture of carbon monoxide and hydrogen is known as water gas):

$CO+{ H } _{ 2 }O\rightleftharpoons C{ O } _{ 2 }+{ H } _{ 2 }$

Which of the following reactions is an example of a use of water gas in the synthesis of other compounds?

chemistry study of the first element - hydrogen occurrence of hydrogen introduction to hydrogen hydrogen

  1. $CH _4(g) +\ H _2O(g) \xrightarrow[Ni]{1270 K} CO(g) +\ 3H _2(g)$

  2. $CO(g) +\ H _2O(g) \xrightarrow[Catalyst]{673 K} CO _2(g) +\ H _2(g)$

  3. $CnH _{2n+2}(g) +\ nH _2O(g) \xrightarrow[Ni]{1270 K} nCO(g) +\ (2n+1)H _2(g)$

  4. $CO(g) +\ 2H _2(g) \xrightarrow[Catalyst]{Cobalt} CH _3OH(l)$

Show answer
Correct Option: D
Explanation:

Carbon monoxide and hydrogen react over a catalyst to produce methanol. Today, the most widely used catalyst is a mixture of copper and zinc oxides, supported on alumina, as first used by ICI in 1966. At 5–10 MPa (50–100 atm) and 250 °C (482 °F), the reaction is characterized by high selectivity (>99.8%): 

$\\ CO+2{ H } _{ 2 }→C{ H } _{ 3 }OH$

Water gas is also called as syngas

chemistry study of the first element - hydrogen occurrence of hydrogen introduction to hydrogen hydrogen

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Water gas is actually an older terminology. From the view point of composition, they both have the same components: Hydrogen and carbon monoxide, with or without some amount of carbon dioxide. However, what is different is the way they are produced. Water gas was usually produced by passing steam over red hot coke. On the other hand syngas is mainly produced industrially by steam reforming of natural gas that involves catalytic decomposition of methane in steam to give the resultant mixture along with the traditional coal gasification and various other methods.

In Syngas-Bosch process,$CO$ is removed from syngas($CO+H _2$) by:

chemistry study of the first element - hydrogen occurrence of hydrogen introduction to hydrogen hydrogen

  1. reducing to coke

  2. oxidising to carbon dioxide

  3. using density difference

  4. all of the above

Show answer
Correct Option: B
Explanation:

 This process of removal of $CO$ from syngas uses the water-gas shift reaction:

$CO + H _2O \longrightarrow CO _2 + H _2$

Which method is used to remove $CO$ from syngas($CO+H _2$) during Syngas Bosch process?

chemistry study of the first element - hydrogen occurrence of hydrogen introduction to hydrogen hydrogen

  1. Oxidation by using $KMnO _4$

  2. Oxidation by mixing steam

  3. Oxidation by using $K _2Cr _2O _7$

  4. All of these

Show answer
Correct Option: B
Explanation:

 This process of removal of $CO$ from syngas uses the water-gas shift reaction:

$CO + H _2O(steam) \longrightarrow CO _2 + H _2$

The formation of atomic hydrogen is favored at:

chemistry study of the first element - hydrogen occurrence of hydrogen introduction to hydrogen hydrogen

  1. high temperature and low pressure

  2. low pressure and high temperature

  3. high temperature and high pressure

  4. low temperature and low pressure

Show answer
Correct Option: A
Explanation:

The formation of atomic hydrogen is favored at high temperature and low pressure. The enthalpy of formation of atomic hydrogen is 217.97 kJ. This is the enthalpy change when a mole of atomic hydrogen is formed by dissociating 1/2 mole of molecular hydrogen (the more stable state of the element).)

Water gas is mixed with steam and the mixture is passed over heated $Fe _{2}O _{3}$ in presence of $Cr _{2}O _{3}.$
The mixture when passed in water dissolves $CO _{2}$ and dihydro gen left undissolved is collected. This method of preparation of hydrogen gas is known as:

chemistry study of the first element - hydrogen occurrence of hydrogen introduction to hydrogen hydrogen

  1. Bosch process

  2. Lane process

  3. Kellner process

  4. Hall process

Show answer
Correct Option: A
Explanation:

For the commercial preparation of dihydrogen, Bosch process is used.


In Bosch's process, water gas (i.e. $CO+H _2$ ) is mixed with twice of its volume of steam in presence of catalysts $Fe _2O _3$ and $Cr _2O _3$ or $ThO _2$ where $Cr _2O _3$ acts as promoter. It gives the products $CO _2$ and $H _2$. Now, $CO _2$ is dissolved in water & removed leaving $H _2$ behind which is undissolved.