Chemistry: Alcohol

• What are alcohols defined as in organic chemistry?

  Compounds where one or more hydrogen atoms in an alkane are replaced by an -OH group.
• What is the general formula for alcohols?

  C_nH_2n+1OH
• Why is ethanol used in cosmetic products?

  It contains a denaturant to deter human consumption.
• What is the INCI designation for ethanol?

  Alcohol (denat.) or Specially Denatured Alcohol.

  
• What does SD stand for in SD Alcohol?

  Specially Denatured.

  
• What is an example of SD Alcohol and its components?

  SD Alcohol 3-A is Ethanol + Methanol.
• How is a primary (1°) alcohol defined?

  The carbon with the -OH group is attached to only one alkyl group.
• How is a secondary (2°) alcohol defined?

  The carbon with the -OH group is joined directly to two alkyl groups.
• How is a tertiary (3°) alcohol defined?

  The carbon holding the -OH group is attached directly to three alkyl groups.
• What are fatty alcohols and their characteristics?

  • High-molecular-weight, straight-chain primary alcohols
  • Usually have an even number of carbon atoms
  • Single alcohol group (-OH) attached to the terminal carbon
• What are some examples of iso alcohols?

  • 4-Methyl-1-pentanol (Isohexyl alcohol)
  • 3-methyl-1-butanol (Isopentyl alcohol)
  • 2-methylpropan-1-ol (Isobutyl alcohol)
  • Isopropanol (2-Propanol)
• How do fatty alcohols behave in terms of surfactants?

  • They are amphipathic
  • Act as non-ionic surfactants
  • Used as co-emulsifiers, emollients, and thickeners in cosmetics and food
• Why do alcohols have higher boiling points than alkanes?

  Alcohols can form hydrogen bonds, requiring more energy to break them.

  
• What is the relationship between the number of carbon atoms in alcohols and their boiling points?

  Boiling points increase as the number of carbon atoms increases.

  
• How does hydrogen bonding affect the physical properties of alcohols?

  Hydrogen bonding influences their boiling points and solubility in water.
• What are the types of intermolecular forces present in alcohols?

  Hydrogen bonding, van der Waals dipole-dipole interactions, and van der Waals dispersion forces.
• Why do alcohols have lower volatility compared to alkanes?

  Alcohols have stronger hydrogen bonds than the van der Waals forces in alkanes.
• How does the solubility of alcohols in water change with the length of the hydrocarbon chain?

  Solubility decreases as the length of the hydrocarbon chain increases.
• What happens to the solubility of alcohols with four or more carbon atoms?

  They are considered immiscible in water.
• What is the main intermolecular attraction in both pure water and pure ethanol?

  Hydrogen bonds.

  
• What occurs when water and ethanol are mixed?

  New hydrogen bonds are formed between water and ethanol molecules.

  
• How do long hydrocarbon chains affect the solubility of alcohols in water?

  They disrupt hydrogen bonding between water molecules, reducing solubility.
• What is phenol in terms of its chemical structure?

  It is an aromatic alcohol with an -OH group attached to a benzene ring.

  
• What are the physical properties of pure phenol?

  It is a white crystalline solid with a disinfectant smell and causes skin blistering.
• How do the intermolecular interactions of phenol compare to toluene?

  Phenol has stronger permanent dipole-dipole attractions and hydrogen bonding.

  
• What are the melting and boiling points of phenol?

  Melting point: 40-43 °C, Boiling point: 182 °C.
• Why does phenol have a higher melting and boiling point compared to toluene?

  Due to stronger intermolecular interactions, including hydrogen bonds.

  
• What are the terms that can be confusing in the context of phenols and related compounds?

  • Phenyl (group)
  • Phenol (compound)
  • Benzene (compound)
  • Benzyl (group)