Organic Chemistry - iGCSE Double Science: Chemistry

What are the atoms in a hydrocarbon?

What are the atoms in a hydrocarbon?

Carbon and Hydrogen only

What is a homologous series?

group of compounds that can all be represented by the same formula

What is a functional group?

A group of atoms that can determine how a compound typically reacts

What are the first six stem words for carbon atoms according to the IUPAC system?

• meth-

• eth-

• prop-

• hex-

• pent-

• but-

what is the suffix for a single bond?

-ane

what is the suffix for a double bond?

-ene

What are the ways that you can represent Organic Compounds? (5)

• Structural formula

• Displayed formula

• Molecular formula

• General formula

• Empirical Formula

What does the General Formula show you?

describes any member of a family of compounds (Algebraic)

What does the Empirical Formula show you?

simplest whole number ratio

What does the Molecular Formula show you?

actual number of atoms

What does the Displayed Formula show you?

SHows how atoms are arranged

What does the Structural Formula show you?

Carbon by carbon

What is crude oil?

mixture of carbons

What is the first part of Fractional distillation process?

The oil is heated until most of its liquid is turned into gas

What is the second part of the Fractional distillation process?

since there's a temperature gradient, when the substances that make up crude oil reach a part of the column lower than their boiling point they condense

What happens to the longer hydrocarbons in fractional distillation

the longer hydrocarbons that have high boiling points condense early on

What happens to the longer hydrocarbons in fractional distillation

the shorter hydrocarbons that have low boiling points condense later on the top

What do bubble caps do?

Stop the seperated liquids from remixing

What are the names of the main fractions obtained from crude oil in decreasing order? (6)

• Refinery gases

• Gasoline

• Kerosene

• Diesel

• Fuel Oil

• Bitumen

What is the use of Refinery Gases?

Domestic heating

What is the use of Gasoline?

Fuel in cars

What is the use of Kerosene?

Fuel for Aircraft

What is the use of Diesel?

Fuel for larger vehicles

What is the use of Fuel oil?

Fuel for large ships

What is the use of Bitumen?

To surface roads and roofs

What is the trend in colour of the fractions?

As structure increases, it gets darker

What is the trend in boiling point of the fractions?

As the hydrocarbon structure increases, the boiling point increases

What is the trend in viscosity of the fractions?

As the chain lengths for the hydrocarbon increase, it becomes more viscous

When fuel is burned, what does it release?

It releases heat energy

what does incomplete combustion produce?

Carbon Monoxide and Soot

How can Carbon Monoxide affect the red blood cells?

It can combine with red blood cells and stop it from carrying oxygen

in cars, when temperature gets too high, what happens to the nitrogen and oxygen?

When temperatures get high enough for the oxygen and the nitrogen to make Nitrogen oxides

what compounds can be made when fuel is burnt?

sulphur dioxide and nitrogen oxides

WHat compounds form sulphur dioxide and nitrogen oxides mix with the vapour in clouds?

dilute sulfuric acid and nitric acid

What happens when rain has dilute sulfuric acid and nitric acid

it is acid rain

What is cracking?

Thermal decomposition reaction, breaking down molecules bby heating them

What are the conditions for catalyst craking?

• Catalyst

• Heat: 600-700

WHat is the catalyst for catalyst cracking?

Silia or Alumina

What temperature does the catalyst has to be?

600-700

Why do people do cracking?

Because of the demand for shorter chain hydrocarbons is more than longer chained hydrocarbons

Alkanes are ______________ hydrocarbons

saturated

Alkenes are ______________ hydrocarbons

unsaturated

WHat is the general formula for alkanes?

GnH2n + 2n + 2

How does substitution reaction work?

A hydrogen atom from the alkane is substituted by chlorine or bromine form the UV light

Alkenes have a _______ Double bond

C=C

What is the general formula for alkenes?

CnH2n

Why are alkenes known to be unsaturated?

Because they have a double carbon bond

What is the word equation for complete combustion?

hydrocarbon + oxygen -> Carbon dioxide + water

WHat is the functional group of Alkenes?

C=C

Why are alkenes unsaturated?

Because they have a double carbon bond

What is the Bromine test for?

testing double carbon bonds

What is the colour of the bormine water?

orange

If you mix bromine and an alkene together, what colour will they form?

colourless

Why does bromine change colour?

Because it is reacting to the alkenes, making dibromoalkane, which is colourless

WHat is a polymer?

substances made by joining up lots of small repeating units called monomers

how does addition polymerisation work?

alkenes open up their carbon-carbon bonds and join together to make polymer chains

Why are there problems in the disposal of addition polymers? (2)

• the production of toxic gases when they are burned

• their inertness and inability to biodegrade

what does the polymers inertness prevent the disposal of addtiton polymers?

Most addition polymers are inert (not reactive) because of strong carbon double bonds, which takes a lot of time to biodegrade

what does the production of toxic gases prevent the disposal of addtiton polymers?

Because if you burn plastics they can release toxic gases.