Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Ethanol () is a colorless liquid at room temperature with a distinct smell and burning taste. It is soluble in water in all proportions.
Ethanol reacts with Sodium () to form sodium ethoxide () and evolve hydrogen gas ().
Dehydration of Ethanol: Heating ethanol at with excess concentrated results in the formation of ethene (). Here, acts as a dehydrating agent.
Ethanoic Acid () belongs to the group of carboxylic acids. A solution of ethanoic acid in water is called vinegar.
Glacial Acetic Acid: The melting point of pure ethanoic acid is . It often freezes during winter in cold climates, giving it this name.
Esterification Reaction: Ethanoic acid reacts with absolute ethanol in the presence of an acid catalyst to give an ester (), which is characterized by a sweet smell.
Saponification: Esters react in the presence of an alkali like to give back the alcohol and the sodium salt of the carboxylic acid ().
Reaction with Carbonates: Ethanoic acid reacts with carbonates () and hydrogencarbonates () to produce salt, water, and carbon dioxide () gas.
📐Formulae
💡Examples
Problem 1:
What happens when ethanol is oxidized by alkaline ?
Solution:
Ethanol is converted into ethanoic acid ().
Explanation:
Alkaline acts as an oxidizing agent, adding oxygen to ethanol:
Problem 2:
Explain the chemical test to distinguish between ethanol and ethanoic acid using sodium hydrogencarbonate ().
Solution:
Ethanoic acid reacts with to produce brisk effervescence of gas, while ethanol does not react.
Explanation:
Carboxylic acids like are acidic enough to decompose carbonates and hydrogencarbonates, releasing , whereas alcohols like are neutral/very weakly acidic and fail this test.
Problem 3:
Write the products formed when ethanoic acid reacts with sodium hydroxide ().
Solution:
The products are Sodium Ethanoate () and water ().
Explanation:
This is a neutralization reaction between an acid and a base: