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Flashcards in Organic Chemistry Deck (44)
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1
Q

What is crude oil

A

A mixture of hydrocarbons

2
Q

What does fractional distillation do and explain the process

A

Separates crude oil into fractions. Heated and oil evaporates… smaller molecules condense higher of the tower, larger molecules condensed low down into the tower.

3
Q

What is the role of bitumen

A

For road surfacing

4
Q

What is the role of fuel oil

A

For ships

5
Q

What is the role of diesel

A

Fuel for cars/lorries/busses

6
Q

What is the role of kerosene

A

Aircraft fuel

7
Q

What is the role of gasoline

A

Fuels for cars

8
Q

What is the trend in boiling point of the main fractions

A

The boiling point increases as the number of carbon atoms increases.

9
Q

What is the trend in viscosity of the main fractions

A

Viscosity increases as the number of carbon atoms increases

10
Q

What is the trend in colour of the main fractions.

A

The greater the number of carbon atoms the darker in colour.

11
Q

What is the trend in viscosity of the main fractions

A

Viscosity increases as the number of carbon atoms increase

12
Q

What happens when fuel is burned

A

It releases heat energy(exothermic reaction)

13
Q

What is complete combustion

A

Complete combustion happens in a reaction when there is enough oxygen available producing carbon dioxide and water.

14
Q

Give an example of a complete combustion reaction.

A

Methane + oxygen -> Carbon dioxide + water

CH4 +202 ->CO2 + 2H20

15
Q

What is incomplete combustion

A

Incomplete combustion happens in a reaction when there is not enough oxygen available

16
Q

What are possible products that can be produced in incomplete combustion

A

Carbon monoxide, carbon(soot), carbon dioxide and water

17
Q

Give an example of incomplete combustion

A

Ethane + oxygen -> carbon monoxide + water

C2H6 + 2.5 02 -> 2CO + 3H20

18
Q

How can carbon monoxide be produced

A

Via the incomplete combustion of fuels

19
Q

Give an example of carbon monoxide being produced in incomplete combustion

A

Propane + oxygen -> carbon monoxide + water

C3H8 + 3.5O2 -> 3CO + 4H20

20
Q

Why is carbon monoxide poisonous to humans

A

It reduces the capacity of the blood to carry oxygen

21
Q

What happens when fuels are burned in vehicle engines

A

High temperatures are reached

22
Q

What happens when high temperatures are reached in fuels

A

Nitrogen and oxygen react with the air to produce nitrogen oxides

23
Q

Give an example of nitrogen and oxygen reacting

A

 nitrogen + oxygen -> nitrogen oxides

N2 + O2 -> 2NO

24
Q

What can nitrogen oxides react with in the atmosphere

A

Water to produce HN03

25
Q

What are fossil fuels such as coal gas and oil made up from

A

Crude oil

26
Q

What are fossil fuels

A

Hydrocarbons

27
Q

What impurities can hydrocarbons contain

A

Sulphur

28
Q

If sulphur is present in a hydrocarbon, when burnt what can escape into the atmosphere

A

Sulphur dioxide

29
Q

Name the reaction between sulphur dioxide and oxygen

A

S + O2 -> SO2

30
Q

What can happen when acids form in the atmosphere

A

It can cause acid rain

31
Q

What natural and man-made materials can acid rain destroy

A

Acid rain can kill trees/plants, fish. It can also corrode limestone and marble since they are both made of calcium carbonate. Iron is also attacked by acid rain

32
Q

Give the chemical formula for calcium carbonate

A

CaCO3

33
Q

When sulphur dioxide is present in the atmosphere what can it sometimes react with

A

Water and oxygen to form sulphuric acid. 

34
Q

Give the chemical formula for sulphuric acid

A

(H2SO4)

35
Q

Give the named and balanced equation of sulphur dioxide reacting with water and oxygen

A

Sulphur dioxide + water + oxygen -> Sulphuric Acid

2SO2 + 2H2O + O2 -> 2H2SO4

36
Q

What happens if sulphur dioxide reacts with only water

A

A weak acid is produced called sulphurous acid

37
Q

Give the chemical formula for sulphurous acid

A

H2SO3

38
Q

What is cracking

A

Cracking involves a thermal decomposition of long chain alkanes into shorter chain alkanes and alkenes 

39
Q

Give an example of cracking

A

Decane -> octane + ethene

C10H22 -> C8H18 + C2H4

40
Q

What are the thermal conditions of cracking

A

600°c

41
Q

Given example of catalysts used in cracking

A

Aluminium oxide Al2O3

42
Q

Yes or no crude oil contains excess amount of long chains of hydrocarbons.

A

Yes

43
Q

Why are shorter chain hydrocarbons in greater demand

A

As they take more time and are rarer than long chain hydrocarbons. For example petrol.

44
Q

What can cracking also produce

A

Alkenes used in making polymers and ethanol