Written Section

Question 1

What does the term “equilibrium” mean, when applied to a chemical reaction?

Answer 1

The rate of the forward and backwards reaction are equal.

Question 2

Why is the Haber Process not carried out at a very high temperature?

Answer 2

Because it favours the backwards reaction.

Question 3

The viscosity of alcohols depends on a number of factors:
The strength of the molecule
The size of the molecule
Temperature
These factors can be investigated using alcohols and apparatus from the lists below.
Using your knowledge of chemistry, identify the alcohols and apparatus that you would select and describe how these could be used to investigate one, or more, of the factors affecting the viscosity of alcohols.

Answer 3

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Question 4

How do you identify what is the alcohol and what is the acid in an ester?

Answer 4

To identify the carboxylic acid, they are have a C=O bond.

Then the other side is the alcohol.

Question 5

The ester can be prepared in the lab by heating a mixture of the reactants with a catalyst. What is the catalyst used?

Answer 5

The catalyst used in the reaction is concentrated sulphuric acid

Question 6

What improvement could be made to the experimental set-up shown in the diagram? (For the preparation of an ester).

Answer 6

A condenser

Question 7

What oxidising solutions are used to oxidise alcohols?

Answer 7

Acidified potassium dichromate (orange to green)
Fehlings solution (blue to red)
Tollens reagent (clear to silver mirror)

Question 8

A third isomer of formula C3H8O exists. It’s structure is CH3-CH2-O-CH3. Suggest why it has a lower melting point and boiling point than the alcohols.

Answer 8

Due to the alcohols having a hydrogen bond, requiring more energy to break.

Question 9

How do you draw the amino acids that make up a protein molecule?

Answer 9

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Question 10

Explain why enzymes lose their catalytic activity when heated above a certain temperature?

Answer 10

As enzymes cannot function at high temperatures, it becomes denatured.

Question 11

Drawing the acid produced when you change a product.

Answer 11

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Question 12

Name the following substance

CH3-CH(OH)-CH2-COOH

Answer 12

3-hydroxy butanoic acid

Question 13

Why do free radicals form in the atmosphere?

Answer 13

Due to UV rays which provide enough energy for the bonds to break, forming unstable atoms

Question 14

Identify the 3 steps in the free radical chain reaction.

Answer 14

Initiation: There will be 2 free electrons on the products.
Propagation: there will be a free electron on each side
Termination: there will be 2 electrons on the reactants

Question 15

Soap moles files allow oil to mix with water.

Explain fully the cleaning action of compound C. (Soap)

Answer 15

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