ChemistryChapter 18: Alcohol
Exam Response (alcohols)
Typical tasks: classify 1/2/3; oxidation products + orange/green; distil vs reflux; iodoform; ester name; dehydration to alkene; carbonate v
Learning objectives
- Explain exam response (alcohols) in simple chemical language.
- Connect 1. oxidation with 2. other using equations, observations, or trends where needed.
- Answer a short Federal Board question with the correct terms and a clear reason.
Definition
Typical tasks: classify 1/2/3; oxidation products + orange/green; distil vs reflux; iodoform; ester name; dehydration to alkene; carbonate vs carboxylic. Tertiary: no dichromate change. Classify 1/2/3 before oxidation product prediction. Primary alcohols need distillation to stop at aldehyde; dichromate colour change should be stated.
Important terms
- EXAM RESPONSE (ALCOHOLS)
- Typical tasks: classify 1/2/3; oxidation products + orange/green; distil vs reflux; iodoform; ester name; dehydration to alkene; carbonate vs carboxylic.
- 1. OXIDATION
- Write distil/reflux.
- 2. OTHER
- Dehydrate ethene.
Overview
Oxidation, then other:
Oxidation
Write distil/reflux. Name ethanal/ethanoic from ethanol. Ketone from propan-2-ol. Green Cr3+. Dichromate: state colour change and carbonyl product.
Examples Orange -> green · 3 stays orange · Tollens next chapter
Other
Dehydrate ethene. Esterify ethyl ethanoate. Iodoform ethanol yes. Carbonate no fizz. Iodoform: name yellow ppt CHI3 when methyl alcohol group present.
Examples Conc H2SO4 dehydrate · Conc H2SO4 ester · CHI3 yellow
WHAT — EXAM RESPONSE (ALCOHOLS)
Typical tasks: classify 1/2/3; oxidation products + orange/green; distil vs reflux; iodoform; ester name; dehydration to alkene; carbonate vs carboxylic. Tertiary: no dichromate change. Classify 1/2/3 before oxidation product prediction. Primary alcohols need distillation to stop at aldehyde; dichromate colour change should be stated.
WHY — Why this topic matters
EXAM RESPONSE (ALCOHOLS) 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
OXIDATION: Write distil/reflux. Name ethanal/ethanoic from ethanol. Ketone from propan-2-ol. Green Cr3+. Dichromate: state colour change and carbonyl product. Examples: Orange -> green; 3 stays orange; Tollens next chapter. OTHER: Dehydrate ethene. Esterify ethyl ethanoate. Iodoform ethanol yes. Carbonate no fizz. Iodoform: name yellow ppt CHI3 when methyl alcohol group present. Examples: Conc H2SO4 dehydrate; Conc H2SO4 ester; CHI3 yellow. Worked 4-mark ethanol ox: acidified K2Cr2O7, orange to green distil: ethanal reflux excess: ethanoic acid primary alcohol Primary alcohol to aldehyde needs distillation to avoid further oxidation to acid.
Worked example
- Worked 4-mark ethanol ox:
- acidified K2Cr2O7, orange to green
- distil: ethanal
- reflux excess: ethanoic acid
- primary alcohol
- Primary alcohol to aldehyde needs distillation to avoid further oxidation to acid.
In simple words
Alcohol exams. No spirits, no illicit oxidation or chlorination plants.
Key points
- 1 acid or al, 2 ketone, 3 no
- iodoform needs the methyl fragment
- class first
- conditions
Exam preparation
Exam Focus
Quick revision
Revision Zone
Review the key facts, formulas and checks before you move on.Exam Response (alcohols)
Sticky Notes · Quick Revision
Core Idea
- Typical tasks: classify 1/2/3; oxidation products + orange/green; distil vs reflux; iodoform; ester name; dehydration to alkene; carbonate vs carboxylic. Tertiary: no dichromate change. Classify 1/2/3 before oxidation product prediction. Primary alcohols need distillation to stop at aldehyde; dichromate colour change should be stated.
1. OXIDATION
- Write distil/reflux. Name ethanal/ethanoic from ethanol. Ketone from propan-2-ol. Green Cr3+. Dichromate: state colour change and carbonyl product.
- Orange -> green
- 3 stays orange
- Tollens next chapter
2. OTHER
- Dehydrate ethene. Esterify ethyl ethanoate. Iodoform ethanol yes. Carbonate no fizz. Iodoform: name yellow ppt CHI3 when methyl alcohol group present.
- Conc H2SO4 dehydrate
- Conc H2SO4 ester
- CHI3 yellow
Exam Example
- Worked 4-mark ethanol ox:
- acidified K2Cr2O7, orange to green
- distil: ethanal
- reflux excess: ethanoic acid
- primary alcohol
- Primary alcohol to aldehyde needs distillation to avoid further oxidation to acid.
Common Misconceptions
- Do not confuse 1. OXIDATION with 2. OTHER; state the difference before giving an example.
- Writing only “1 acid or al, 2 ketone, 3 no” is not enough. Explain what it means in a complete sentence.
FBISE Exam Check
- Explain exam response (alcohols), compare its two main parts, and include the correct chemical evidence.
- Alcohol exams. No spirits, no illicit oxidation or chlorination plants.
60-second revision
- Typical tasks: classify 1/2/3; oxidation products + orange/green; distil vs reflux; iodoform; ester name; dehydration to alkene; carbonate vs carboxylic.
- 1. OXIDATION: Write distil/reflux.
- 2. OTHER: Dehydrate ethene.
- Exam reminder: Worked 4-mark ethanol ox: acidified K2Cr2O7, orange to green distil: ethanal reflux excess: ethanoic acid primary alcohol Primary alcohol to aldehyde needs distillation to avoid further oxidation to acid.
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