Question 1: Define an alcohol in terms of its chemical structure.

Answer: An alcohol is an organic compound containing one or more hydroxyl (-OH) groups attached to a carbon atom.

Question 2: Explain why alcohols are generally soluble in water.

Answer: Because of the hydroxyl (-OH) group, which can form hydrogen bonds with water molecules, making alcohols soluble.

Question 3: Describe the mechanism by which alcohols are formed from alkenes.

Answer: Alcohols are formed from alkenes through a hydration reaction, where water (H2O) adds across the carbon-carbon double bond in the presence of an acid catalyst, resulting in an alcohol.

Question 4: What is the general formula for primary alcohols?

Answer: CₙH₂ₙ+1OH

Question 1: Calculate the molar mass of ethanol (C₂H₅OH).

Answer: Molar mass = (2 × 12.01) + (6 × 1.008) + (16.00) = 46.068 g/mol

Question 2: If 10 grams of ethanol are burned completely, how many moles are involved? (Use molar mass = 46.07 g/mol)

Answer: Number of moles = 10 g / 46.07 g/mol ≈ 0.217 moles

Question 1: Describe a simple experiment to test for the presence of a hydroxyl group in an unknown compound.

Answer: Add a small amount of the compound to a solution of sodium metal; if hydrogen gas is released, it indicates the presence of a hydroxyl group.

Question 2: List two safety precautions to observe when handling alcohols in the laboratory.

Answer: Use in a well-ventilated area to prevent inhalation of vapors and keep away from open flames due to their flammability.

Question 3: Identify the variable that should be kept constant when testing the solubility of different alcohols in water.

Answer: The temperature of the water sample.

Question 1: A sample of an unknown alcohol dissolves completely in water at room temperature. What can you infer about its polarity and structure?

Answer: The alcohol is likely polar with a hydroxyl group, and possibly a small molecular size, which enhances its solubility.

Question 1: Explain the difference between primary, secondary, and tertiary alcohols with examples. (6 marks)

Answer: Primary alcohols have the hydroxyl group attached to a carbon atom that is only connected to one other carbon (e.g., ethanol). Secondary alcohols have the hydroxyl attached to a carbon connected to two other carbons (e.g., isopropanol). Tertiary alcohols have the hydroxyl attached to a carbon connected to three other carbons (e.g., tert-butanol).

Question 2: Describe the process of fermentation to produce ethanol, including key reactants and conditions.

Answer: Fermentation is a biological process where yeast converts sugars, such as glucose, into ethanol and carbon dioxide under anaerobic conditions, usually at temperatures around 30°C.

Question 1: Name two uses of ethanol in everyday life.

Answer: Ethanol is used as a disinfectant in hand sanitizers and as a fuel additive in gasoline.

Question 2: Explain how alcohols are involved in the manufacture of plastics and pharmaceuticals.

Answer: Alcohols serve as key intermediates in the synthesis of plastics such as polyethylene glycol and are used in pharmaceutical formulations as solvents, antiseptics, and intermediates in drug synthesis.