Question 1: Define an ester and describe its general chemical structure.

Answer: An ester is an organic compound derived from a carboxylic acid and an alcohol, characterized by the general formula RCOOR', where R and R' are hydrocarbon groups.

Question 2: Explain how esters are formed through a chemical reaction.

Answer: Esters are formed by a reaction called esterification, where a carboxylic acid reacts with an alcohol in the presence of an acid catalyst, producing an ester and water.

Question 1: Given the ester ethyl acetate, with the molecular formula C4H8O2, calculate the number of carbon, hydrogen, and oxygen atoms in one molecule.

Answer: Carbon: 4, Hydrogen: 8, Oxygen: 2

Question 2: If a molecule of butyl formate has the molecular formula C4H8O2, determine its molar mass. (Use atomic masses: C=12.01, H=1.008, O=16.00 g/mol)

Answer: Molar mass = (4×12.01) + (8×1.008) + (2×16.00) = 48.04 + 8.064 + 32.00 = 88.104 g/mol

Question 1: Describe the typical steps involved in preparing esters in a laboratory setting.

Answer: Mixing a carboxylic acid with an alcohol in the presence of a small amount of sulfuric acid catalyst, heating the mixture, and then separating the ester from the reaction mixture.

Question 2: Identify two safety precautions to consider when performing esterification experiments.

Answer: Wearing safety goggles and working in a well-ventilated area to avoid inhaling fumes.

Question 1: A sample of an ester has a pungent smell similar to pineapple. Which type of ester is likely present? Explain your reasoning.

Answer: It is likely an ethyl or methyl ester, as these esters often have fruity, pineapple-like odors due to their volatile nature.

Question 2: Explain how esters are used in industry and daily life.

Answer: Esters are used as flavorings and fragrances in food, perfumes, and cosmetics. They are also employed in the production of plastics, solvents, and artificial flavors, contributing to their widespread industrial and household applications.

Question 1: Describe the esterification process, including the reactants, catalyst, and the products formed. (6 marks)

Answer: Esterification is a chemical reaction where a carboxylic acid reacts with an alcohol in the presence of an acid catalyst, typically sulfuric acid. The reaction produces an ester and water. The process involves heating the mixture, allowing the acid and alcohol to combine and form the ester, which can then be separated and purified.