Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Combustion: Carbon and its compounds burn in the presence of oxygen to produce , water vapor, heat, and light. Saturated hydrocarbons generally give a clean blue flame, while unsaturated hydrocarbons give a yellow sooty flame due to incomplete combustion.
Oxidation: Carbon compounds can be easily oxidized. For example, alcohols are converted to carboxylic acids using oxidizing agents like alkaline (Potassium Permanganate) or acidified (Potassium Dichromate).
Addition Reaction: Unsaturated hydrocarbons add hydrogen in the presence of catalysts like or to form saturated hydrocarbons. This process is called hydrogenation and is used to convert vegetable oils (unsaturated) into vegetable ghee (saturated).
Substitution Reaction: In saturated hydrocarbons, hydrogen atoms can be replaced by other atoms like chlorine in the presence of sunlight. This is a rapid reaction yielding a series of products.
Esterification: The reaction between an alcohol and a carboxylic acid in the presence of an acid catalyst to produce a sweet-smelling substance called an ester.
Saponification: The reaction of an ester with a base like to produce the parent alcohol and the sodium salt of the carboxylic acid (soap).
📐Formulae
💡Examples
Problem 1:
Identify the product formed when reacts with alkaline and heat.
Solution:
(Ethanoic acid)
Explanation:
Alkaline acts as a strong oxidizing agent. It adds oxygen to Ethanol () to convert the hydroxyl group into a carboxyl group, resulting in Ethanoic acid ().
Problem 2:
Explain the reaction used to test for unsaturation in hydrocarbons using Bromine water.
Solution:
Explanation:
Unsaturated hydrocarbons (alkenes/alkynes) undergo an Addition Reaction with Bromine water (). The reddish-brown color of bromine disappears (decolorization) as it adds across the double or triple bond, while saturated hydrocarbons do not react with bromine water under normal conditions.
Problem 3:
Write the chemical equation for the reaction between Ethanoic acid and Sodium Carbonate.
Solution:
Explanation:
Ethanoic acid reacts with carbonates to produce a salt (Sodium Ethanoate), water, and Carbon Dioxide gas. The evolution of causes brisk effervescence.