ChemistryChapter 21: Organic Synthesis
Tests To Check the Product
Br2 water: C=C. KMnO4 mild: C=C.
Learning objectives
- Explain tests to check the product in simple chemical language.
- Connect 1. c=c and c-x with 2. o and n using equations, observations, or trends where needed.
- Answer a short Federal Board question with the correct terms and a clear reason.
Definition
Br2 water: C=C. KMnO4 mild: C=C. Tollens/Fehling: aldehyde. DNPH: carbonyl. Iodoform: methyl carbonyl or ethanol-type. Carbonate: COOH. AgNO3 ethanolic: X- from haloalkane (speed 3>2>1). PCl5 fumes: OH or COOH. Litmus: acid vs amine. Meaning: after a paper synthesis, say how you would confirm — still names, not a full analytical SOP. Tollens, iodoform, bromine water, FeCl3 phenol — match test to functional group expected. Count carbons after each synthetic step; silent carbon loss is the most common multi-step mistake.
Mathematical form
C=C. KMnO4 mild
C=C. Tollens/Fehling
Important terms
- TESTS TO CHECK THE PRODUCT
- Br2 water: C=C.
- 1. C=C AND C-X
- Br2 fade.
- 2. O AND N
- Tollens mirror.
Overview
Unsaturation and X, then O and N:
C=c and C-X
Br2 fade. AgNO3 ppt colour + NH3 (halogen chapter). Beilstein named if the book has a copper-wire halogen clue. Wrong test wastes marks — aldehyde needs Tollens not DNPH alone for distinction.
Examples Orange fade · AgCl white · Cream AgBr
O and N
Tollens mirror. Carbonate fizz. Iodoform yellow. HNO2 bubbles for 1 aliphatic amine. DNPH orange. Record observation: colour, ppt, gas — exam table format.
Examples Mirror al · Fizz acid · CHI3 · N2 amine
WHAT — TESTS TO CHECK THE PRODUCT
Br2 water: C=C. KMnO4 mild: C=C. Tollens/Fehling: aldehyde. DNPH: carbonyl. Iodoform: methyl carbonyl or ethanol-type. Carbonate: COOH. AgNO3 ethanolic: X- from haloalkane (speed 3>2>1). PCl5 fumes: OH or COOH. Litmus: acid vs amine. Meaning: after a paper synthesis, say how you would confirm — still names, not a full analytical SOP. Tollens, iodoform, bromine water, FeCl3 phenol — match test to functional group expected. Count carbons after each synthetic step; silent carbon loss is the most common multi-step mistake.
WHY — Why this topic matters
TESTS TO CHECK THE PRODUCT is an independent FBISE learning unit because students must use its definitions, conditions, equations, or trends separately in explanations and calculations.
HOW — How it works
C=C AND C-X: Br2 fade. AgNO3 ppt colour + NH3 (halogen chapter). Beilstein named if the book has a copper-wire halogen clue. Wrong test wastes marks — aldehyde needs Tollens not DNPH alone for distinction. Examples: Orange fade; AgCl white; Cream AgBr. O AND N: Tollens mirror. Carbonate fizz. Iodoform yellow. HNO2 bubbles for 1 aliphatic amine. DNPH orange. Record observation: colour, ppt, gas — exam table format. Examples: Mirror al; Fizz acid; CHI3; N2 amine. Exam confirm ethanol vs ethanal: ethanal: Tollens mirror, DNPH ppt ethanol: no mirror; iodoform yes; PCl5 fumes stack, do not use one test alone if two groups possible
In simple words
ID names. No unknown-poison full forensics protocol.
Key points
- one test per group
- stack if needed
- colour changes
- positive tables
Exam preparation
Exam Focus
Quick revision
Revision Zone
Review the key facts, formulas and checks before you move on.Tests To Check the Product
Sticky Notes · Quick Revision
Core Idea
- Br2 water: C=C. KMnO4 mild: C=C. Tollens/Fehling: aldehyde. DNPH: carbonyl. Iodoform: methyl carbonyl or ethanol-type. Carbonate: COOH. AgNO3 ethanolic: X- from haloalkane (speed 3>2>1). PCl5 fumes: OH or COOH. Litmus: acid vs amine. Meaning: after a paper synthesis, say how you would confirm — still names, not a full analytical SOP. Tollens, iodoform, bromine water, FeCl3 phenol — match test to functional group expected. Count carbons after each synthetic step; silent carbon loss is the most common multi-step mistake.
1. C=C AND C-X
- Br2 fade. AgNO3 ppt colour + NH3 (halogen chapter). Beilstein named if the book has a copper-wire halogen clue. Wrong test wastes marks — aldehyde needs Tollens not DNPH alone for distinction.
- Orange fade
- AgCl white
- Cream AgBr
2. O AND N
- Tollens mirror. Carbonate fizz. Iodoform yellow. HNO2 bubbles for 1 aliphatic amine. DNPH orange. Record observation: colour, ppt, gas — exam table format.
- Mirror al
- Fizz acid
- CHI3
- N2 amine
Exam Example
- Exam confirm ethanol vs ethanal:
- ethanal: Tollens mirror, DNPH ppt
- ethanol: no mirror; iodoform yes; PCl5 fumes
- stack, do not use one test alone if two groups possible
Common Misconceptions
- Do not confuse 1. C=C AND C-X with 2. O AND N; state the difference before giving an example.
- Writing only “one test per group” is not enough. Explain what it means in a complete sentence.
FBISE Exam Check
- Explain tests to check the product, compare its two main parts, and include the correct chemical evidence.
- ID names. No unknown-poison full forensics protocol.
60-second revision
- Br2 water: C=C.
- 1. C=C AND C-X: Br2 fade.
- 2. O AND N: Tollens mirror.
- Exam reminder: Exam confirm ethanol vs ethanal: ethanal: Tollens mirror, DNPH ppt ethanol: no mirror; iodoform yes; PCl5 fumes stack, do not use one test alone if two groups possible
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