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Alkanes — Reactions
Combustion: CO2 + H2O if complete; CO / C if not (air chapter). Substitution with Cl2 in UV (free radical named): CH4 + Cl2 -> CH3Cl + HCl as a type, not a chlorination plant. Cracking named in energy. Source: crude oil fraction; cracking makes shorter alkanes and alkenes. This page separates the idea from the wider topic “ALKANES” so it can be revised and assessed on its own.
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Alkanes — Reactions
What is it?
Combustion: CO2 + H2O if complete; CO / C if not (air chapter). Substitution with Cl2 in UV (free radical named): CH4 + Cl2 -> CH3Cl + HCl as a type, not a chlorination plant. Cracking named in energy. Source: crude oil fraction; cracking makes shorter alkanes and alkenes. This page separates the idea from the wider topic “ALKANES” so it can be revised and assessed on its own.
In simple words
- Combustion: CO2 + H2O if complete; CO / C if not (air chapter).
- Blue flame complete
- Exam link: combustion + named sub.
Important terms
REACTIONS: Combustion: CO2 + H2O if complete; CO / C if not (air chapter).
ALKANES: Alkanes are saturated hydrocarbons: only C-C and C-H single bonds.
What you should learn
- Define reactions using accurate chemistry terms.
- Explain why reactions matters within alkanes.
- Apply the learning unit to an FBISE-style example, comparison, diagram, or calculation.
Examples
- Blue flame complete
- UV / Cl2 named
- No other easy addition
KEY IDEA
Combustion: CO2 + H2O if complete; CO / C if not (air chapter). Substitution with Cl2 in UV (free radical named): CH4 + Cl2 -> CH3Cl + HCl as a type, not a chlorination plant. Cracking named in energy. Source: crude oil fraction; cracking makes shorter alkanes and alkenes.
EXAM APPLICATION
Exam alkane: saturated, CnH2n+2 main reaction: combustion Cl2 / UV substitution named, not a factory
Recommended for Class 11
Full school-level explanation
Combustion: CO2 + H2O if complete; CO / C if not (air chapter). Substitution with Cl2 in UV (free radical named): CH4 + Cl2 -> CH3Cl + HCl as a type, not a chlorination plant. Cracking named in energy. Source: crude oil fraction; cracking makes shorter alkanes and alkenes. This page separates the idea from the wider topic “ALKANES” so it can be revised and assessed on its own.
Study this learning unit in three steps:
WHAT — ALKANES — REACTIONS
Combustion: CO2 + H2O if complete; CO / C if not (air chapter). Substitution with Cl2 in UV (free radical named): CH4 + Cl2 -> CH3Cl + HCl as a type, not a chlorination plant. Cracking named in energy. Source: crude oil fraction; cracking makes shorter alkanes and alkenes. This page separates the idea from the wider topic “ALKANES” so it can be revised and assessed on its own.
WHY — Why this topic matters
ALKANES — REACTIONS 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
Combustion: CO2 + H2O if complete; CO / C if not (air chapter). Substitution with Cl2 in UV (free radical named): CH4 + Cl2 -> CH3Cl + HCl as a type, not a chlorination plant. Cracking named in energy. Source: crude oil fraction; cracking makes shorter alkanes and alkenes. Examples: Blue flame complete; UV / Cl2 named; No other easy addition. Exam use: Exam alkane: saturated, CnH2n+2 main reaction: combustion Cl2 / UV substitution named, not a factory
KEY IDEA
Combustion: CO2 + H2O if complete; CO / C if not (air chapter). Substitution with Cl2 in UV (free radical named): CH4 + Cl2 -> CH3Cl + HCl as a type, not a chlorination plant. Cracking named in energy. Source: crude oil fraction; cracking makes shorter alkanes and alkenes.
Remember
- combustion + named sub
Examples
- Blue flame complete
- UV / Cl2 named
- No other easy addition
EXAM APPLICATION
Exam alkane: saturated, CnH2n+2 main reaction: combustion Cl2 / UV substitution named, not a factory
Remember
- burn + named sub
Examples
- Blue flame complete
- UV / Cl2 named
- No other easy addition
Remember
- combustion + named sub
- burn + named sub
- Federal Board only
- combustion + named sub
- burn + named sub
- combustion + named sub
- independent learning unit
- combustion + named sub
How the ideas connect
Combustion: CO2 + H2O if complete; CO / C if not (air chapter). Substitution with Cl2 in UV (free radical named): CH4 + Cl2 -> CH3Cl + HCl as a type, not a chlorination plant. Cracking named in energy. Source: crude oil fraction; cracking makes shorter alkanes and alkenes. Examples: Blue flame complete; UV / Cl2 named; No other easy addition. Exam use: Exam alkane: saturated, CnH2n+2 main reaction: combustion Cl2 / UV substitution named, not a factory
Deeper understanding
Go beyond memorising Alkanes — Reactions. Connect the definition to reasons, relationships, exceptions, and exam wording.
How the ideas connect
Combustion: CO2 + H2O if complete; CO / C if not (air chapter). Substitution with Cl2 in UV (free radical named): CH4 + Cl2 -> CH3Cl + HCl as a type, not a chlorination plant. Cracking named in energy. Source: crude oil fraction; cracking makes shorter alkanes and alkenes. Examples: Blue flame complete; UV / Cl2 named; No other easy addition. Exam use: Exam alkane: saturated, CnH2n+2 main reaction: combustion Cl2 / UV substitution named, not a factory
Common mistakes
Exam focus
Core idea
WHAT
WHY
HOW
Exam focus
Quick revision
- combustion + named sub
- burn + named sub
- Federal Board only
- REACTIONS: Combustion: CO2 + H2O if complete; CO / C if not (air chapter).
- ALKANES: Alkanes are saturated hydrocarbons: only C-C and C-H single bonds.
- WHAT — ALKANES — REACTIONS: Combustion: CO2 + H2O if complete; CO / C if not (air chapter). Substitution with Cl2 in UV (free ra
Federal Board Class 11 Chemistry learning unit. Easy wording; no provincial-board material added.
For long answers on Alkanes — Reactions: define clearly → explain the main parts → give one example → state one exam caution.
Exam Focus
Exam Focus
Important points
- combustion + named sub
- burn + named sub
- Federal Board only
- REACTIONS: Combustion: CO2 + H2O if complete; CO / C if not (air chapter).
Important formulas
- combustion + named sub
- burn + named sub
- Federal Board only
Common exam traps
- Do not treat reactions as the same as every other part of alkanes; define this unit and use its own evidence, steps, or conditions.
- Do not memorise a label alone; connect the definition to a process, structure, condition, equation, or example.
Long question structure
Definition → key parts → example → exam caution
Common Mistakes
Common Mistakes
- Mistake
Do not treat reactions as the same as every other part of alkanes; define this unit and use its own evidence, steps, or conditions.
- Mistake
Do not memorise a label alone; connect the definition to a process, structure, condition, equation, or example.
- Mistake
Do not use provincial-board wording or add material outside the Federal Board Class 11 scope.
- Mistake
Federal Board Class 11 Chemistry learning unit. Easy wording; no provincial-board material added.
Revision Zone
60-Second Revision
Quick cues from this topic — use them for last-minute revision.
combustion + named sub
burn + named sub
Federal Board only
REACTIONS: Combustion: CO2 + H2O if complete; CO / C if not (air chapter).
Combustion: CO2 + H2O if complete; CO / C if not (air chapter). Substitution with Cl2 in UV (free radical named): CH4 + Cl2 -> CH3Cl + HCl as a type, not a chlo
- Definition
- Combustion: CO2 + H2O if complete; CO / C if not (air chapter). Substitution with Cl2 in UV (free radical named): CH4 + Cl2 -> CH3Cl + HCl as a type, not a chlo
- Example
- Blue flame complete
- Critical warning
- Do not treat reactions as the same as every other part of alkanes; define this unit and use its own evidence, steps, or
Did you understand this topic?
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Exam Practice
Define
Q1. Define Alkanes — Reactions.
Explain
Q2. Explain: KEY IDEA.
Example
Q3. Give one clear example of Alkanes — Reactions and say why it fits.
Mistake
Q4. State one common mistake students make about Alkanes — Reactions.
Exam note
Q5. Write a short exam note on Alkanes — Reactions: definition, two points, one example.
Sources & References
School-standard facts for Matric and Intermediate. Original explanations — not copied from textbooks.