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C7 Organic Chemistry

Last updated about 1 month ago
44 questions
4.7.1.1 Crude oil, hydrocarbons and alkanes
1

The prefix for 3 carbons is but-

1

The general formula for alkanes is:

7
Have a general formula of ____________
each molecule differs from the last by ________
Trends down the series:
1. Melting points and boiling points _____________
2. Volatility ______________
3. Flammability ______________
4. Viscosity ______________
5. Intermolecular forces _____________
Other Answer Choices:
increase
increases
decreases
CnH2n+2
CH2
1

Name the alkane

1

Crude oil is a mixture of hydrocarbons. Most of these hydrocarbons are alkanes.

The general formula of an alkane is CnH2n+2

Complete the structural formula for the alkane that has six carbon atoms in its molecules.

(This question will not return an answer until it is looked at by Miss Bryant)

1

Crude oil contains a large number of hydrocarbons.

Crude oil is a finite resource.

What is a finite resource?

Tick (✓) one box.

1

What is crude oil formed from?

Tick (✓) one box.

1

This diagram shows a reaction which takes place in an oil refinery.



X, Y and Z are all examples of which type of compound?

1

Suggest one use for compound Z.

5

Match the alkane name to its molecular formula

Draggable itemCorresponding Item
Butane
CH4
Pentane
C2H6
Propane
C3H8
Methane
C4H10
Ethane
C5H12
1

This is a hydrocarbon

1

This is a hydrocarbon

1

This is a hydrocarbon

1

This is a hydrocarbon

1

This is a hydrocarbon

1

The molecule in the previous question is...

1

A hexane molecule has 6 carbon atoms in the chain. How many hydrogen atoms are there?

1

The chemical formulae for ethane is...

1

Fossil fuels are a renewable resource

1

Crude oil is formed when...

2

Hydrocarbons are compounds made of...

4.7.1.2 Fractional distillation and petrochemicals
1

What is fractional distillation?

2

Which of the following are examples of components that can be separated using fractional distillation?

1

Fractional distillation is an example of a physical separation technique.

1

The alkanes from crude oil are separated into fractions by fractional distillation.

Explain how this is done and why it separates the alkanes into fractions.

1

Fractions are mixtures of substances with similar boiling points – they are not pure substances. How can you tell that they are mixtures and not pure substances.

3

5.20 kg of crude oil contains 1.53 kg of LPG (Liquefied Petroleum Gas).

Calculate the percentage (%) of LPG in 5.20 kg of crude oil.

Give your answer to 3 significant figures.

4

Describe how a fractioning column separates crude oil.

1

In a fractioning column, compounds are separated by...

1

Where would the least flammable compounds be found?

1

Where would would the most volatile compounds be found?

1

Where would the smallest and shortest alkanes be found?

1

What is fractional distillation?

1

Fractional distillation is an example of a physical separation technique.

4.7.1.3 Properties of hydrocarbons
8
Describe the relationship shown by the graph and use ideas about forces between molecules to explain this relationship.

1. The more carbons the higher the ____________ point.
2. The _________ carbons the larger the molecules.
3. Larger molecules have ___________ boiling points
4. Larger molecules have larger forces ____________ them
5. The larger the forces between the molecules the more ___________ is required for them to break out of a liquid and become a ________
6. The more energy needed to _____________ the molecules, the higher the boiling point of the hydrocarbon
7. The larger / more the forces between the ______________, the higher the boiling point.
Other Answer Choices:
higher
between
gas
molecules
more
separate
energy
boiling
4
1. Bonds between __________ do not break ;
2. Forces between ______________ (intermolecular forces) are overcome
3. Bonds between atoms are ___________
4. Forces between molecules are _________ ;
Other Answer Choices:
atoms
weak
molecules
strong
9
All alkanes are:
1. _________________ (contain carbon and hydrogen _________
2. ______________ (contain all ___________ bonds)
3. ______________(can be combusted.)
4. have strong _____________ bonds between the __________
5. have weak ___________________ forces between ______________
Other Answer Choices:
atoms
covalent
molecules
hydrocarbons
saturated
single
flammable
ONLY
intermolecular
6

Trends for alkanes as the carbon chain gets longer

  • Volatility
  • Melting and boiling points
  • Height of point of condensation in fractional distillation column
  • strength of intermolecular forces
  • Viscosity
  • Flammability
  • Increase
  • Decreases
1
Alkanes burn in oxygen. Balance the equation for methane burning.

Put numbers in each box - that number could be 1.

_______ CH4 + _______ O2 ⟶ _______ CO2 + _______ H2O
4.7.1.4 Cracking and alkenes
1

Ethene is an alkene.

Which reagent is used to test for alkenes?

1
Here is an equation for cracking. Complete the equation

C30H62 → C10H22 + _______
1
Hydrocarbons can be cracked to produce more useful molecules.

 Complete the sentence.

Choose the answer from these: Alloys Fertilisers Fuels

Some products of cracking are useful as  _______ .
1

From the previous question, What type of chemical reaction takes place when compound X is converted into compounds Y and Z?

1

Compounds Y and Z are both useful substances.Compound Y is unsaturated. Compound Z is saturated.

Suggest one use for compound Y.

4.7.2.1 Structure and formulae of alkenes
4.7.2.2 Reactions of alkenes
4.7.2.3 Alcohols
4.7.2.4 Carboxylic acids
4.7.3 Synthetic and naturally occurring polymers