Standard Grade RevisionUnit 15

Q1. The box contains the names of some processes.

 

respiration cracking distillation

  filtration photosynthesis galvanising

 

(a) Identify the process which produces water and carbon dioxide.

(b) Identify the process which can be used to separate alcohol and water.

Standard Grade Chemistry

(a) Respiration.

(b) Distillation.

Q2. The box contains the names of some chemical reactions and processes.

  combustion neutralisation polymerisation

  addition cracking electrolysis

 

(a) Identify the chemical reaction in which oxygen is used up.

(b) Identify the process in which a compound is broken

down by electricity.

(c) Identify the chemical reaction in which glucose molecules

join together to form starch.

(a) Combustion.

(b) Electrolysis.

(c) Polymeristaion.

Q3. Starch and glucose are carbohydrates.

(a) Which chemical would you use to test for starch?

(b) What is the chemical name for the alcohol produced by the fermentation of glucose?

(c) The percentage of alcohol in wine depends on the temperature of the fermentation process.

Some results are shown on the graph.

 

Standard Grade Chemistry

(i) Describe how the temperature of fermentation affects the % alcohol produced? (ii) Use the graph to estimate the % alcohol when the temperature is 37oC

(a) Iodine (turns blue black). (b) Ethanol.

(c) (i) As the temperature increases the percentage of alcohol decreases.

(ii) 12.5%

Unit 15 Revision

Standard Grade Chemistry

Q4. The bar chart shows the boiling points of some alcohols.

(a) Describe the relationship between the number of carbon atoms and the

boiling point.

(b) Predict the boiling point of the alcohol with five carbon atoms per molecule.

(c) Ethanol is the name of the alcohol with two carbon atoms per molecule. What would be the name of the alcohol with one carbon atom per molecule?

(a) As the number of carbon atoms in the molecule increases the boiling point increases.

(b) 130oC

(c) Methanol.

Unit 15 Revision.

Standard Grade Chemistry

Q5. Alcoholic drinks contain different percentages of alcohol.

Beers contain 5% but some ciders are stronger at 7.5%. Red wine contains 12%, but

fortified wines contain 18%. Whisky is much stronger at 40% alcohol.

(a) Present the above information in a table with suitable headings.

(b) All alcoholic drinks are made using the same process:

glucose alcohol + carbon dioxide

(i) What type of substance, found in yeast, acts as a catalyst for the reaction?

(ii) What is the correct chemical name for the alcohol found in alcoholic drinks?

(iii) State a test for carbon dioxide.

(a) Alcoholic drink Percentage Alcohol / %

Beers 5

Ciders 7.5

Red wine 12

Fortified wine 18

Whisky 40

(b) (i) Enzyme (zymase) (ii) Ethanol

(iii) Turns lime water chalky (or milky)

Unit 15 Revision.

Standard Grade Chemistry

Q6. The equations represent chemical reactions involving carbohydrates.

A carbon dioxide + water glucose + oxygen

B glucose starch + water

C starch + water glucose

D glucose ethanol + carbon dioxide

E glucose + oxygen carbon dioxide + water

(a) Identify the reaction which is catalysed by enzymes in yeast.

(b) Identify the hydrolysis reaction.

(c) Identify the reaction which takes place in animals during respiration.

Q7. Various reagents can be used to identify substances

A Benedict’s solution

B bromine solution

C ferroxyl indicator

D iodine solution

E lime water

a) Identify the reagent used to test for starch.

b) Identify the reagent used to test for glucose

(a) D

(b) C

(c) E

(a) D

(b) A

Standard Grade Chemistry

Unit 15 Revision.Q8. Glucose, sucrose and starch are carbohydrates.

Identify the two correct statements.

 

A Glucose molecules join together with a loss of water.

B Starch is a polymer made from sucrose molecules.

C Sucrose turns warm Benedict’s solution orange.

D Glucose is an isomer of sucrose.

E Starch dissolves easily in water.

F Sucrose can be hydrolysed.

A and F

Q9. The equation shows the reaction in which glucose is converted into

ethanol (alcohol).

C6H12O6 2C2H5OH + 2CO2

(a) What name is given to this process?

(b) Calculate the mass of ethanol that is obtained when 60 kg of glucose is

totally converted into alcohol.

(a) Fermentation (b) 32kg

Unit 15 Revision.

Standard Grade Chemistry

Q. Methanol can take part in many chemical reactions.

(a) (i) Compound X has the molecular formula CH2O.

Draw the full structural formula for compound X.

(ii) Methanol is changed into compound X by dehydrogenation.

Suggest what is meant by dehydrogenation.  

(b) In carbonylation, methanol reacts with compound Y forming

only ethanoic acid.

Suggest a name for compound Y.

(a)(i) H

C=O

H

(ii) Loss of hydrogen

(b) Carbon monoxide

Unit 15 Revision.

Standard Grade Chemistry

Q. The flow diagram shows what happens to starchy foods after they have been eaten.

((a) What type of substance, present in the digestive system, speeds up the

breakdown of starchy foods?

(b) What type of chemical reaction takes place when starch is broken down into

glucose during digestion.

(c) Process Y provides the body with energy.

Name this process.

(d) Name an isomer of glucose.(a) Enzyme (b) Hydrolysis (c) Respiration

(d) Fructose

Unit 15 Revision.

Standard Grade Chemistry

Q Ailsa carried out the experiment shown below.

(a) What type of chemical reaction takes place when starch is heated

with hydrochloric acid?

(b) Ailsa said that the starch had turned into glucose.

Name another sugar which turns Benedict’s solution red/orange.

(c) Ailsa repeated her experiment using amylase solution instead

of hydrochloric acid.

Suggest a reason why the Benedict’s solution did not tune red/orange.

(a) Hydrolysis

(b) Fructose or

maltose.

(c) Acid has

denatured

the enzyme