Table of contents

1. Matter and Measurements4h 31m
2. Atoms and the Periodic Table5h 23m
3. Ionic Compounds2h 18m
4. Molecular Compounds2h 18m
5. Classification & Balancing of Chemical Reactions3h 17m
6. Chemical Reactions & Quantities2h 27m
7. Energy, Rate and Equilibrium3h 46m
8. Gases, Liquids and Solids3h 25m
9. Solutions4h 10m
10. Acids and Bases3h 29m
11. Nuclear Chemistry56m
BONUS: Lab Techniques and Procedures1h 38m
BONUS: Mathematical Operations and Functions47m
12. Introduction to Organic Chemistry1h 34m
13. Alkenes, Alkynes, and Aromatic Compounds2h 12m
14. Compounds with Oxygen or Sulfur1h 6m
15. Aldehydes and Ketones1h 1m
16. Carboxylic Acids and Their Derivatives1h 11m
17. Amines39m
18. Amino Acids and Proteins1h 51m
19. Enzymes1h 37m
20. Carbohydrates1h 41m
21. The Generation of Biochemical Energy2h 8m
22. Carbohydrate Metabolism2h 22m
23. Lipids2h 26m
24. Lipid Metabolism1h 45m
25. Protein and Amino Acid Metabolism1h 37m
26. Nucleic Acids and Protein Synthesis2h 54m

17. Amines

Functional Group Priorities

GOB Chemistry

17. Amines

Functional Group Priorities

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Problem 61

Textbook Question

Lemon juice, which contains citric acid, is traditionally recommended for removing the odor associated with cleaning fish. What functional group is responsible for a 'fishy' odor, and why does lemon juice work to remove the odor? If possible, test this at home using a piece of fish.

Verified step by step guidance

Identify the functional group responsible for the 'fishy' odor. The 'fishy' odor is typically caused by amines, which are organic compounds containing the functional group \( \text{R-NH}_2 \) (primary amines), \( \text{R}_2\text{NH} \) (secondary amines), or \( \text{R}_3\text{N} \) (tertiary amines). These compounds are basic and volatile, contributing to the strong odor.

Understand the chemical properties of citric acid in lemon juice. Citric acid is a weak organic acid with the formula \( \text{C}_6\text{H}_8\text{O}_7 \). It contains carboxylic acid groups \( \text{-COOH} \), which can donate protons (\( \text{H}^+ \)) in an acid-base reaction.

Explain the reaction between amines and citric acid. When amines (basic) come into contact with citric acid (acidic), an acid-base reaction occurs. The amines accept protons from the citric acid, forming ammonium ions \( \text{R-NH}_3^+ \), which are non-volatile and odorless.

Describe why this reaction removes the odor. The conversion of volatile amines to non-volatile ammonium ions eliminates the 'fishy' smell because the ammonium ions do not evaporate into the air as easily as the amines do.

Optional experiment: To test this at home, rub a piece of fish with lemon juice and observe the reduction in odor. This demonstrates the acid-base reaction between citric acid and the amines present in the fish, neutralizing the odor.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Functional Groups

Functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. In the context of odors, certain functional groups, such as amines, are known to produce 'fishy' smells due to their structure and the way they interact with receptors in our noses.

Citric Acid

Citric acid is a weak organic acid found in citrus fruits, including lemons. It has the ability to neutralize basic compounds, such as amines, which are often responsible for unpleasant odors. By reacting with these compounds, citric acid can effectively mask or eliminate the 'fishy' smell associated with fish.

Odor Neutralization

Odor neutralization refers to the process of eliminating or masking unpleasant smells through chemical reactions or absorption. In the case of lemon juice, the citric acid interacts with the odor-causing compounds, altering their structure and reducing their volatility, which diminishes the perception of the 'fishy' odor.

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