Taken from the NSW Board of Studies past School Certificate Examination Papers
Year 10
Understanding chemicals
School Certificate Questions
1. The diagram shows liquid in a measuring cylinder.
From which position should the reading be taken to give the most accurate volume of
the liquid?
(A) P
(B) Q
(C) R
(D) S
2. What is the chemical formula for sulfuric acid?
(A) H2SO4
(B) HS4O
(C) H4SO2
(D) HS(OH)4
Use this information to answer Questions 3 and 4.
3. What does X represent in this equation?
(A) carbon dioxide
(B) calcium sulfate
(C) hydrogen
(D) sulfuric hydroxide
4. What is the name of this type of chemical reaction?
(A) Combustion
(B) Corrosion
(C) Decomposition
(D) Neutralisation
Taken from the NSW Board of Studies past School Certificate Examination Papers
5. Under certain conditions, when copper oxide is heated with carbon, the copper
oxide will lose oxygen and copper will be formed. The oxygen will combine with the
carbon to form carbon monoxide.
Which set of diagrams represents this reaction?
6. What is the name of the solution represented by the formula HCl?
(A) Hydrochloric acid
(B) Hydrogen chlorine
(C) Sulfur hydroxide
(D) Sulfuric acid
7. Jamie and Joanne mixed two clear, colourless liquids. A solid formed as the liquids
mixed. What type of reaction were they observing?
(A) Absorption
(B) Combustion
(C) Corrosion
(D) Precipitation
8. What happens to atoms during a decomposition reaction?
(A) They are created.
(B) They are destroyed.
(C) They are rearranged to form more substances.
(D) They are rearranged to form fewer substances.
9. Why are indicators used in chemical experiments?
(A) To identify chemical conditions
(B) To change the colour of chemicals
(C) To show when a reaction is occurring
(D) To make chemical reactions occur more quickly
Taken from the NSW Board of Studies past School Certificate Examination Papers
10. The formation of water from hydrogen and oxygen can be represented as follows:
What scientific idea about the formation of new compounds is represented by this?
(A) Matter is created.
(B) Matter becomes heavier.
(C) Atoms can be rearranged.
(D) Atoms can change their shape.
Some properties of chemicals X and Y are listed in the table.
11. A mixture of equal amounts of X and Y is placed in a beaker of acid at 70°C.
From this information, which statement is correct?
(A) X will melt and Y will dissolve.
(B) X will react and Y will not melt.
(C) X will not melt and Y will dissolve.
(D) X will not react and Y will not melt.
Read the following description of substance Z.
12. Which of the following could be the chemical formula of Z?
(A) H2O
(B) H2SO4
(C) NaOH
(D) NH4OH
Taken from the NSW Board of Studies past School Certificate Examination Papers
Use this information to answer Questions 13-15.
Two active metals X and Y were placed in separate containers of dilute acid. The
volumes of gas produced as the metals reacted with acid were recorded at regular
intervals. The results are shown in the graph.
13. Which statement about the chemical reactions in the first 5 minutes is correct?
(A) X produces gas faster than Y.
(B) Y produces gas faster than X.
(C) X and Y produce gas equally quickly.
(D) There is insufficient information to decide which metal produces gas faster.
14. What is the best explanation for the shape of the graph for metal Y after 5
minutes?
(A) A large amount of Y was added to the acid.
(B) Y stopped producing gas at 5 minutes.
(C) More Y was used than X.
(D) All Y was used up before 5 minutes had passed.
15. What names could be given to metals X and Y? (You may refer to the Periodic
Table to help you answer this question.)
16. Which reaction is a combustion reaction?
(A) Adding hydrochloric acid to sodium hydroxide
(B) Adding sulfuric acid to calcium carbonate
(C) Igniting a piece of magnesium metal
(D) Mixing solutions of lead nitrate and sodium chloride
Taken from the NSW Board of Studies past School Certificate Examination Papers
Use the diagram to answer Questions 17-19.
The diagram shows the steps in the formation and decomposition of ozone in the
atmosphere.
17. Which choice (A)–(D) correctly identifies a molecule of ozone?
Taken from the NSW Board of Studies past School Certificate Examination Papers
18. Four of the steps do not have descriptive statements. These missing statements are
shown in the following table in NO PARTICULAR ORDER.
Which descriptive statement refers to step 7?
(A) P
(B) Q
(C) R
(D) S
19. The oxygen molecule formed in step 6 can react with a nitrogen molecule (N2)
when lightning strikes. The product of this reaction is nitrogen monoxide (NO)
molecules.
Which diagram best represents this reaction?
Taken from the NSW Board of Studies past School Certificate Examination Papers
Use this information to answer Questions 20 and 21.
Air conditioning refrigerants (ACRs) are identified by a 3 digit numbering system.
20. How many hydrogen atoms does ACR – 022 have?
(A) 0
(B) 1
(C) 2
(D) 3
21. Which ACR is represented by the diagram below?
(A) ACR – 122
(B) ACR – 123
(C) ACR – 223
(D) ACR – 233
22. Which of the following is a correct equation for the reaction of an acid and a
metal?
(A) Acid metal →water salt
(B) Acid metal →hydrogen salt
(C) Acid metal →oxygen water
(D) Acid metal →carbon dioxide water
Taken from the NSW Board of Studies past School Certificate Examination Papers
23. The industrial production of lime (CaO) involves the heating of limestone
(CaCO3) as shown by this equation:
This process is an example of which type of reaction?
(A) Combustion
(B) Corrosion
(C) Decomposition
(D) Neutralisation
24. Complete the following chemical equation:
25. Name the type of chemical reaction represented by the equation above.
26. Complete the following general word equation.
27. Litmus, phenolphthalein and some plant extracts are examples of chemicals that
change colour when added to acid or alkali.
Name this group of chemicals.
28. A common group of chemical compounds contains these substances:
Name this group of chemical compounds.
29. State the scientific name for substances that can combine in a chemical reaction.
30. Use the following key to answer the question.
Kim wants to identify a rock. She cannot see any crystals with the naked eye. She
performs two tests on the rock and observes that it does not react with dilute acid and
it does not burn.
From the key, identify the rock.
Taken from the NSW Board of Studies past School Certificate Examination Papers
31. What type of chemical reaction is the rusting of iron?
32. The diagram shows a test tube containing an acid. A piece of substance Q is
added.
(a) Q is a shiny-grey substance that can conduct electricity. What type of substance
is Q?
(b) (i) Identify ONE risk in this experiment.
(ii) Describe ONE safety precaution that would reduce this risk
.
(c) What are THREE observations that could be made when the acid begins to react
with substance Q?