[Answers] In each reaction box, place the best reagent and conditions from the list below.

The sequence of reactions is a very common organic chemical reaction. How do select in each reaction box, place the best reagent and conditions from the list below. There are million and trillion chemicals in the organic molecule. It is constructed with carbon, hydrogen, oxygen, sulfur, phosphorus, and nitrogen, etc.

What is hydrocarbon

Hydrocarbon is the first basic organic molecule in the field of organic chemistry. It is built with the help of carbon and hydrogen atoms. Methane is the first simplest hydrocarbon on the list. CH4 is the molecular formula of methane. It contains four hydrogen atoms and one central carbon atom.

In the normal atmospheric condition, it is gas. It is known as natural gas. During the combustion reaction, four hydrogen atoms of methane give water molecule and one carbon atom give only one carbon dioxide(CO2). In this way, methane reduces carbon emissions.

If there is one hydrogen atom less in methane, it is called a methyl group (CH3-). After the combining of two methyl groups gives ethane (CH3-CH3 or C2H6). In the same way, we can construct a long chain of the molecule, which is similar to the polymer.

Adding the methyl group to the organic molecule gives more molecular mass to the molecule. Methane molecule is gas in nature. Ethane molecule contains two carbon and six hydrogen atoms. It can be denoted with a simple formula.

C_nH_(2n+2)

Here, n= number of carbon atom

The longer chain of 32 carbon with 66 hydrogen atoms forms wax. Which is soft solid matter. This indicated clearly that moving from small to high carbon numbers. The hydrocarbon molecule moving from gas to soft solid matter.

These all hydrocarbon is called aliphatic hydrocarbon. It may form cyclic hydrocarbon also. There is another type of hydrocarbon is called aromatic hydrocarbon.

In each reaction box, place the best reagent and conditions from the list below.[Hydrocarbon reaction]

Q-1: Convert hexane to benzene

In the following figure, hexane is converted into cyclohexane, then cyclohexane is converted into benzene. In each reaction box, place the best reagent and conditions from the list below.

List of reagent and condition for question-1

Step-1: Catalyst,25C Step-2: 5 atm (-H2)	Step-1: Catalyst,500C Step-2: 5-10 atm (-H2)	Step-1: Catalyst,2500C Step-2: 10-20 atm (-H2)
Step-1: Catalyst,250C Step-2: 5 atm (-H2)	Step-1: Catalyst,500C Step-2: 10-20 atm (-H2)	Step-1: Catalyst,300C Step-2: 10-20 atm (-H2)

Explanation for question-1:

1. Hexane is the six member linear chain molecule.
2. In the first step, hexane is converted into cyclohexane in the presence of catalyst at 500 C.
3. In the second step, cyclohexane is converted into benzene with the elimination of hydrogen at 10-20 atm pressure.

Q-2: Convert sodium benzoate to benzene

In the following figure, sodium benzoate is converted into benzene.in each reaction box, place the best reagent and conditions from the list below.

List of reagent and condition for question-2

NaOH, CaO	C2H5ONa, CaO	CH3COONa, CaO
NaOH, CaCl2	NaOH, Ca(OH)2	CH3ONa, CaO

Explanation for question-2:

1. Sodium benzoate is the organic salt of benzoic acid.
2. When sodium benzoate is reacted with sodium hydroxide (NaOH) and calcium oxide(CaO).
3. It removes the CO2 from the sodium benzoate and gives benzene.

Q-3: Convert acetylene to benzene

In the following figure, acetylene is converted into benzene. In each reaction box, place the best reagent and conditions from the list below.

List of reagent and condition for question-3

Heat	Heat in normal tube	High pressure
Red hot tube	catalyst, 200 C	Autoclave

Explanation for question-3:

1. Acetylene is the derivative of ethane molecule. It is the triple bonded molecule.
2. When acetylene is reacted in the presence of red hot tube.
3. Three acetylene molecule fused together forms benzene molecule.

Q-4: Convert phenol to benzene

In the following figure, phenol is converted into benzene. In each reaction box, place the best reagent and conditions from the list below.

List of reagent and condition for question-5

Na dust	Cu dust	Zn dust
Al-Hg alloy	copper tube	Fe dust

Explanation for question-4:

1. Phenole is the derivative of benzene molecule. It is the parent aromatic molecule.
2. When phenol is reacted in the presence of Zn dust catalyst.
3. Hydroxyl group is removed from the phenol molecule.

Q-5: Convert chlorobenzene to benzene

In the following figure, chlorobenzene is converted into benzene.in each reaction box, place the best reagent and conditions from the list below.

List of reagent and condition for question-5

Ni-Al alloy/NaOH	Zn-Hg alloy/NaOH	B-Hg alloy/NaOH
Al-Hg alloy/NaOH	Fe-Hg alloy/NaOH	Pt-Hg alloy/NaOH

Explanation for question-5:

1. Chlorobenzene is the derivative of benzene molecule. It is the parent aromatic molecule.
2. When chlorobenzene is reacted with hydrogen in the presence of Ni-Al alloy catalyst in the alkaline (NaOH condition).
3. Chloro group group is removed from the chlorobenzene molecule molecule.

Q-6: Convert Benzenesulphonic acid to Benzene

In the following figure, Benzenesulphonic acid is converted into benzene. In each reaction box, place the best reagent and conditions from the list below.

List of reagent and condition for question-6

150-200 C	100-150 C	100-140 C
100-200 C	100-130C	100-120 C

Explanation for question-6:

1. Benzenesulphonic acid is the derivative of benzene molecule. It is the parent aromatic molecule.
2. When benzenesulphonic acid is reacted with water at 150-200 C.
3. Benzene formed with the elimination of sulphuric acid .

Q-7: Convert Benzenediazonium chloride to Benzene

In the following figure, Benzenediazonium chloride is converted into benzene. In each reaction box, place the best reagent and conditions from the list below.

List of reagent and condition for question-7

ZnCl2/NaOH	SnCl2/NaOH	SbCl2/NaOH
PbCl2/NaOH	CaCl2/NaOH	CuCl2/NaOH

Explanation for question-7:

1. Benzenediazonium chloride is the derivative of benzene molecule. It is the parent aromatic molecule.
2. When benzenediazonium chloride is reacted with hydrogen in the presence of SnCl2/NaOH.
3. Benzene formed with the elimination of nitrogen and hydrochloric acid .

Q-8: Convert Benzenediazonium chloride to Benzene in the presence of hypophosphorous acid

In the following figure, Benzenediazonium chloride is converted into benzene in the presence of hypophosphorous acid. In each reaction box, place the best reagent and conditions from the list below.

List of reagent and condition for question-8

Cu+	Cu2+	Zn2+
Hg2+	Ca2+	Fe2+

Explanation for question-7:

1. Benzenediazonium chloride is the derivative of benzene molecule. It is the parent aromatic molecule.
2. When benzenediazonium chloride is reacted with hypophosphorous acid in the presence of Cu+.
3. Benzene formed with the elimination of nitrogen, phosphoric acid and hydrochloric acid .

The polarity of the molecules

The polarity of the molecules are listed as follows

• Polarity of BeCl2
• Polarity of SF4
• Polarity of CH2Cl2
• Polarity of NH3
• Polarity of XeF4
• Polarity of BF3
• Polarity of NH4+
• Polarity of CHCl3
• Polarity of BrF3
• Polarity of BrF5
• Polarity of SO3
• Polarity of SCl2
• Polarity of PCl3
• Polarity of H2S
• polarity of CS2
• Polarity of NO2+
• Polarity of HBr
• Polarity of HCl
• Polarity of CH3F
• Polarity of SO2
• Polarity of CH4

Lewis Structure and Molecular Geometry

Lewis structure and molecular geometry of molecules are listed below

• CH4 Lewis structure and CH4 Molecular geometry
• BeCl2 Lewis Structure and BeCl2 Molecular geometry
• SF4 Lewis Structure and SF4 Molecular geometry
• CH2Cl2 Lewis Structure and CH2Cl2 Molecular geometry
• NH3 Lewis Structure and NH3 Molecular geometry
• XeF4 Lewis Structure and XeF4 Molecular geometry
• BF3 Lewis Structure and BF3 Molecular geometry
• NH4+ Lewis Structure and NH4+ Molecular geometry
• CHCl3 Lewis Structure and CHCl3 Molecular geometry
• BrF3 Lewis Structure and BrF3 Molecular geometry
• BrF5 Lewis Structure and BrF5 Molecular geometry
• SO3 Lewis Structure and SO3 Molecular geometry
• SCl2 Lewis structure and SCl2 Molecular Geometry
• PCl3 Lewis structure and PCl3 Molecular Geometry
• H2S Lewis structure and H2S Molecular Geometry
• NO2+ Lewis structure and NO2+ Molecular Geometry
• HBr Lewis structure and HBr Molecular Geometry
• CS2 Lewis structure and CS2 Molecular Geometry
• CH3F Lewis structure and CH3F Molecular Geometry
• SO2 Lewis structure and SO2 Molecular Geometry
• HCl Lewis structure and HCl Molecular Geometry
• HF Lewis structure and HF Molecular Geometry
• HI Lewis structure and HI Molecular Geometry
• CO2 Lewis structure and CO2 Molecular Geometry
• SF2 Lewis structure and SF2 Molecular Geometry
• SBr2 Lewis structure and SBr2 Molecular Geometry
• PF3 Lewis structure and PF3 Molecular Geometry
• PBr3 Lewis structure and PBr3 Molecular Geometry
• CH3Cl Lewis structure and CH3Cl Molecular Geometry
• CH3Br Lewis structure and CH3Br Molecular Geometry
• CH3I Lewis structure and CH3I Molecular Geometry
• SCl4 Lewis structure and SCl4 Molecular Geometry
• SBr4 Lewis structure and SBr4 Molecular Geometry
• CH2F2 Lewis structure and CH2F2 Molecular Geometry
• CH2Br2 Lewis structure and CH2Br2 Molecular Geometry
• XeCl4 Lewis structure and XeCl4 Molecular Geometry
• BCl3 Lewis structure and BCl3 Molecular Geometry