ANS:C - both (a) & (b)

The correct answer is: Neither (a) nor (b). Styrene butadiene rubber (SBR) is produced from the polymerization of styrene and butadiene. Ethyl alcohol and ethylene are not starting materials for SBR. Ethyl alcohol, also known as ethanol, is a volatile, flammable, colorless liquid with the chemical formula C2H5OHC_2H_5OHC2​H5​OH. It is commonly used in alcoholic beverages, as a fuel or fuel additive, and in various industrial applications. Here are some key points about ethyl alcohol:

Properties

• Chemical Formula: C2H5OHC_2H_5OHC2​H5​OH
• Molecular Weight: 46.07 g/mol
• Boiling Point: 78.37 °C (173.07 °F)
• Melting Point: -114.1 °C (-173.4 °F)
• Density: 0.789 g/cm³ at 20 °C

Uses

1. Beverages: Ethanol is the active ingredient in alcoholic drinks. It is produced through the fermentation of sugars by yeast.
2. Fuel: Ethanol can be used as a biofuel or fuel additive. It is often blended with gasoline to create ethanol-blended fuels like E10 (10% ethanol, 90% gasoline).
3. Solvent: It is widely used as a solvent in the pharmaceutical, cosmetics, and chemical industries due to its ability to dissolve a wide range of substances.
4. Antiseptic: Ethanol is used in hand sanitizers and disinfectants because of its antibacterial properties.
5. Industrial Applications: It is used in the manufacture of personal care products, paints, varnishes, and perfumes.

Production

Ethanol can be produced through two main processes:

1. Fermentation: This is the most common method for producing ethanol for beverages and some industrial uses. Sugars from crops like corn, sugarcane, or other biomass are fermented by yeast.
2. Ethylene Hydration: Ethanol can also be synthesized from ethylene (a petrochemical) through a process called acid-catalyzed hydration. This is primarily used for industrial ethanol production.

Chemical Reactions

Ethanol participates in several chemical reactions:

• Combustion: Ethanol burns in air to produce carbon dioxide, water, and heat. C2H5OH+3O2→2CO2+3H2O+energyC_2H_5OH + 3O_2 \rightarrow 2CO_2 + 3H_2O + \text{energy}C2​H5​OH+3O2​→2CO2​+3H2​O+energy
• Dehydration: Ethanol can be dehydrated to produce ethylene. C2H5OH→acidC2H4+H2OC_2H_5OH \xrightarrow{\text{acid}} C_2H_4 + H_2OC2​H5​OHacid​C2​H4​+H2​O
• Oxidation: Ethanol can be oxidized to produce acetaldehyde and further to acetic acid. C2H5OH+[O]→CH3CHO+H2OC_2H_5OH + [O] \rightarrow CH_3CHO + H_2OC2​H5​OH+[O]→CH3​CHO+H2​O

Ethanol is a versatile chemical with a wide range of applications, from everyday use in alcoholic beverages to industrial applications in fuels and solvents. Ethylene is a hydrocarbon with the formula C2H4C_2H_4C2​H4​. It is the simplest alkene (a hydrocarbon with carbon-carbon double bonds) and is an important organic chemical in industry. Here are key points about ethylene:

Properties

• Chemical Formula: C2H4C_2H_4C2​H4​
• Molecular Weight: 28.05 g/mol
• Boiling Point: -103.7 °C (-154.7 °F)
• Melting Point: -169.4 °C (-272.9 °F)
• Density: 1.178 kg/m³ at 15 °C

Uses

1. Polymer Production: Ethylene is a primary feedstock for the production of polyethylene, the most common plastic. It is also used to produce other polymers like polyvinyl chloride (PVC) and polystyrene.
2. Chemical Intermediate: Ethylene is a key raw material in the manufacture of chemicals like ethylene oxide, ethylene glycol, and ethanol.
3. Ripening Agent: In agriculture, ethylene is used as a plant hormone to ripen fruits such as bananas and tomatoes.
4. Industrial Applications: Ethylene is used in the production of antifreeze, solvents, and detergents.

Production

Ethylene is primarily produced through the steam cracking of hydrocarbons such as:

1. Natural Gas: Methane, ethane, and propane can be cracked to produce ethylene.
2. Crude Oil: Naphtha, a fraction of crude oil, can be used as a feedstock in steam cracking.

Chemical Reactions

Ethylene participates in several important chemical reactions:

• Polymerization: Ethylene molecules can join together to form polyethylene, a widely used plastic. nC2H4→−(C2H4)n−nC_2H_4 \rightarrow -(C_2H_4)_n-nC2​H4​→−(C2​H4​)n​−
• Oxidation: Ethylene can be oxidized to produce ethylene oxide, a precursor to ethylene glycol (used in antifreeze and polyester production). C2H4+12O2→C2H4OC_2H_4 + \frac{1}{2}O_2 \rightarrow C_2H_4OC2​H4​+21​O2​→C2​H4​O
• Hydration: Ethylene can react with water in the presence of a catalyst to produce ethanol. C2H4+H2O→C2H5OHC_2H_4 + H_2O \rightarrow C_2H_5OHC2​H4​+H2​O→C2​H5​OH

Industrial Importance

Ethylene is a crucial building block in the petrochemical industry. Its derivatives are used to make a wide range of products that are integral to modern life, including plastics, antifreeze, solvents, and fibers. Ethylene's versatility and reactivity make it one of the most important chemicals in industrial chemistry, driving the production of numerous synthetic materials and chemicals.