Organic Chemistry 1

Hydrocarbons are compounds made of which elements only?

Hydrogen and Carbon

When naming organic compounds

what chain should you find first?

How should alkyl groups be listed when naming compounds?

Alphabetically

What should you use if there are multiple identical groups on the same carbon?

Di- for 2

What is a homologous series?

Series of compounds with the same functional group and general formula

What is the functional group of an alkene?

C=C

What is the chemical test for an alkene?

Shake with bromine in hexane

What is the positive observation for an alkene test?

Orange to colourless solution

What is the negative observation for an alkene test?

Remains orange solution

What is the functional group of an alkane?

C-C

What is the chemical test for an alkane?

Shake with bromine in hexane

What is the positive observation for an alkane test?

Remains orange solution

What is the negative observation for an alkane test?

Orange to colourless solution

What is the functional group of a halogenoalkane?

R-X

What is the chemical test for a halogenoalkane?

Add ethanol then silver nitrate (AgNO₃)

What is the positive observation for a halogenoalkane test?

PPT formed: white (RCl), cream (RBr), yellow (RI)

What is the negative observation for a halogenoalkane test?

Remains colourless solution

What is the functional group of an alcohol?

ROH

What is the chemical test for an alcohol?

Add solid PCl₅ to pure substance

What is the positive observation for an alcohol test?

Steamy fumes (HCl)

What is the negative observation for an alcohol test?

No steamy fumes produced

How can you distinguish a primary alcohol?

Warm with acidified potassium dichromate and distill

What is the positive observation for a primary alcohol?

Orange to green solution

How can you distinguish a secondary alcohol?

Warm with acidified potassium dichromate without distillation

What is the positive observation for a secondary alcohol?

Orange to green solution

What is the observation for a tertiary alcohol?

Remains orange solution

What is the functional group of a carboxylic acid?

RCOOH

What is the chemical test for a carboxylic acid?

Add ethanol and sulfuric acid

What is the positive observation for a carboxylic acid?

Sweet fruity smell

What is the negative observation for a carboxylic acid?

No smell

What is the functional group of a ketone?

RCOR

What is the chemical test for a ketone?

Add Brady’s reagent then Benedicts/Blue Fehlings/Tollens

What is the positive observation for a ketone?

Orange ppt (aromatic) or yellow ppt (aliphatic)

What is the negative observation for a ketone?

Remains orange solution

What reagent does not react with a ketone but reacts with an aldehyde?

Tollen’s reagent

What is the functional group of an aldehyde?

RCOH

What is the chemical test for an aldehyde?

Add Tollen’s reagent or Benedict’s/Fehling’s

What is the positive observation for an aldehyde?

Silver mirror ppt (Tollen’s) or Red ppt (Benedict’s/Fehling’s)

What is the negative observation for an aldehyde?

Remains colourless (Tollen’s) or Remains blue (Benedict’s/Fehling’s)

What is the functional group of an amine?

–NH₂

What is the chemical test for an amine?

Add copper(II) sulfate solution

What is the positive observation for an amine?

Solution turns dark blue from pale blue

What is the negative observation for an amine?

Solution remains pale blue

What is isomerism?

Compounds with the same molecular formula but different structural formulae

What are carbon chain isomers?

Isomers with different carbon chain branching

What are positional isomers?

Isomers with the same functional group but at different positions

What type of isomerism occurs due to restricted rotation around a C=C bond?

E/Z (geometric) isomerism

What is the E/Z naming system based on?

Priority of groups attached to C=C based on atomic number

In E-isomer, where are the high-priority groups?

On opposite sides

In Z-isomer

where are the high-priority groups?

What is the general formula of alkanes?

CₙH₂ₙ₊₂

Why does boiling point increase with longer alkane chains?

More electrons cause stronger London forces

Why do branched alkanes have lower boiling points?

Fewer points of contact and weaker London forces

What is cracking?

Breaking large hydrocarbons into smaller ones

What conditions are used in catalytic cracking?

Zeolite catalyst

What is produced in catalytic cracking?

Mainly alkenes and hydrocarbons of C₅–C₁₀

What is reforming?

Rearranging hydrocarbons into branched/cyclic forms

What pollutants are formed from combustion?

CO

How does a catalytic converter work?

Adsorbs gases, weakens bonds, releases N₂ and CO₂

Name two alternative fuels.

Biodiesel and Bioethanol

What are advantages of biofuels?

Carbon neutral

What are disadvantages of biofuels?

Deforestation

What happens in complete combustion of hydrocarbons?

Produces CO₂ and H₂O

What happens in incomplete combustion of hydrocarbons?

Produces CO

What is a free radical?

A species with an unpaired electron

What conditions are needed for free radical substitution?

UV light and halogen gas

What are the three stages of free radical substitution?

Initiation

What is the formula for alkenes?

CₙH₂ₙ

Why can alkenes form geometric isomers?

Restricted rotation around C=C

How do alkenes react with bromine water?

Decolourises from orange to colourless

How do you convert an alkene to an alkane?

Add H₂ with a Ni catalyst at 170°C

What is an electrophile?

An electron-pair acceptor

What type of bond fission occurs in electrophilic addition?

Heterolytic bond fission

How do you produce a diol from an alkene?

React with acidic potassium manganate(VII)

What is the observation for alkene oxidation with KMnO₄?

Purple to colourless

What happens in addition polymerisation?

Many monomers join to form a polymer

Name three ways to dispose of waste polymers.

Feedstock for cracking, recycling, incineration to release energy.

What are nucleophiles?

Species with a lone pair of electrons that attack δ⁺ carbons

What reaction occurs when halogenoalkanes react with aqueous NaOH?

Nucleophilic substitution to form alcohols

What is formed when halogenoalkanes react with KCN?

Nitriles

What is formed when halogenoalkanes react with ammonia?

Amines

How can you test for halogenoalkanes?

Add ethanol and silver nitrate solution

What precipitate forms with Cl⁻?

White precipitate

What precipitate forms with Br⁻?

Cream precipitate

What precipitate forms with I⁻?

Yellow precipitate

How do you distinguish halide ions with ammonia?

Dilute and concentrated ammonia solubility tests

What is the trend in hydrolysis rate of halogenoalkanes?

Iodo > Bromo > Chloro > Fluoro

Why is hydrolysis faster for iodoalkanes?

Weaker C–I bond

Which type of halogenoalkane hydrolyses fastest?

Tertiary > Secondary > Primary

What mechanism is SN1?

One-step ionisation followed by nucleophile attack

What mechanism is SN2?

One-step nucleophilic attack with transition state

Which mechanism is favoured by tertiary halogenoalkanes?

SN1

Which mechanism is favoured by primary halogenoalkanes?

SN2

What is elimination reaction?

Removal of atoms to form a double bond (alkene)

How do you convert halogenoalkanes to alkenes?

Reflux with concentrated ethanolic KOH

What reagents convert alcohols to chloroalkanes?

Concentrated HCl