Homebush Boys High School

HOMEBUSHBOYSHIGH SCHOOL

YEAR 11 PRELIMINARY

HALF YEARLY EXAMINATION

CHEMISTRY

2009

1 Hour

Student Name……………………………….Teacher……………………..

GENERAL INSTRUCTIONS

Reading time – 5 minutes
Working time –1 hour
Write using blue or black pen
Draw diagram and graphs using pencil
Board approved calculators may be used

TOTAL MARKS – 50

Section I – 15 marks

(Questions 1 – 15)

Section II – 35 marks

(Questions 16 - 23)

A Data Sheet and Periodic Table are provided with this paper

Section I – 15 marks

Attempt Questions 1 – 15. Allow about 15 minutes for this part.

Use the multiple choice answer sheet provided

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1. A mixture of ethanol and water can be separated by:

A centrifugation

B distillation

C decanting

D crystallisation

2. An atom has a mass number of 46 and an atomic number 26. The atom would be:

A iron with 20 neutrons

B iron with 40 neutrons

C zirconium with 20 neutrons

D zirconium with 40 neutrons

3. The following table represents the chemical composition of:

A the biosphere

B the hydrosphere

C the atmosphere

D the lithosphere

4. Which of the following elements is classified as a monatomic molecule?

A nitrogen

B oxygen

C fluorine

D neon

5. Atoms of element Q contains 16 protons, atoms of element R contain 9 protons.

Which one of the following gives the correct formula and bonding type for a compound of Q and R?

A Q2R with ionic bonds

B Q2R with covalent bonds

C QR2 with ionic bonds

D QR2 with covalent bonds

6. The following table contains a selection of cations and anions

Select the set of CORRECT formulae

A SnSO4, NH4(PO4)3, Al(NO3)3

B NH4NO3, Sn3(PO4)2, Al3(SO4)2

C Sn3(PO4)2, NH4(SO4)2, Al(NO3)3

D Al2(SO4)3, (NH4)3PO4, Sn(NO3)2

7. Which of the following is NOT a property of a solid non-metal?

A poor conductor

B malleable

C brittle

D low melting point

8. A hard, rigid substance that would have a very high melting point and be a non-conductor of electricity

in the molten state would be:

A CO2

B SiO2

C PbO2

D TiO2

9. Which of the following compounds would have the highest melting point?

A NaCl

B HCl

C CO2

D SiCl4

10. Examine the crystal lattice below:

This compound would:

A be very hard

B have a low melting point

C conduct electricity well

D be easily distorted

11. Examine the apparatus set up.

It was used by a student in an experiment to determine one

of the significant properties about chemical compounds.

This set up would most likely have been used to determine:

A the melting point of the compound

B the solubility of the compound

C the conductivity of the compound

D the stability of the compound when heated

Solder is a common alloy used in plumbing. Which metals are present in solder?

A brass and copper

B zinc and lead

C lead and tin

D tin and zinc

13. Which of the atom pairs with electron configurations below could form a covalent bond?

A 2,1 and 2,8,5

B 2,4 and 2,8,4

C 2,8,1 and 2,2

D 2,8,8 and 2,7

14. In which of the following do BOTH processes involve physical changes?

A burning coal; evaporating alcohol

B melting sugar; dissolving copper sulfate in water

C boiling water; forming rust on an iron nail

D heating copper carbonate; dissolving sugar in water

15. What type of bonding is shown by the structures given below?

IONIC / COVALENT / METALLIC
A / X / Y / Z
B / Y / X / Z
C / Z / X / Y
D / Y / Z / X

Section II – 35marks

Attempt Questions 16 – 23. Allow about 45 minutes for this part.

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Question 16 (3 marks)

Calcium chloride absorbs moisture from the atmosphere. A 46.75 g sample of moist calcium chloride was heated in a drying oven to remove all the water. The final mass of the sample was 19.08 g

a. Determine the percentage composition of water in the sample 2

……………………………………………………………………………………………………………

b. Write the chemical formula for calcium chloride1

……………………………………………………………………………………………………………

Question 17 (5 marks)

a. Draw the Lewis electron dot diagram for the oxide ion1

b. Draw the Lewis electron dot diagram for the oxygen molecule1

c. What is the name of the compound ZnO? 1

……………………………………………………………………………………………………………

d. Indicate how the formation of bonds in ZnO differ from the formation of bondsin 2

the O2 molecule?

……………………………………………………………………………………………………………

Question 18 (5 marks)

The table below lists the properties of five substances known to be magnesium, diamond, iodine, potassium chloride and hydrogen chloride.

Property / A / B / C / D / E
Melting point (oC) / 3880 / -114 / 650 / 114 / 770
Solid conducts electricity / No / No / Yes / No / No
Soluble in water / No / Yes / Yes / No / Yes
Aqueous solution conducts electricity / N/A / Yes / N/A / N/A / Yes

Use the information in the table to identify substances A, B, C, D & E and justify (give a reason)

your answers

……………………………………………………………………………………………………………

Question 19 (3 marks)

Write the formula for the following:

a. carbon monoxide……………………………………………………………………………………......

b. ammonium hydroxide ……………………………………………………………………………………

c. sodium hydrogen carbonate………………………………………………………………………………

Question 20 (7 marks)

During your course you performed a first hand investigation to compare the properties of TWO elements with the properties of the compound obtained by reacting these two elements.

a. Outline the experimental steps that were necessary for you to carry out this experiment. 5

Present the results you obtained in a table (use at least 1 set of results for each substance)

……………………………………………………………………………………………………………

b. Identify TWO hazards in this experiment, and describe how you dealt with these hazardous 2

situations

……………………………………………………………………………………………………………

Question 21 (3 marks)

Use a copy of the periodic table of the elements to name an element which has:

a)A valency of +2……………………………………………………………………………………..

b)A valency of –1 and is found in period 4……………………………………………………………

c)A member of the actinide series……………………………………………………………………..

d)An alkali metal.………………………………………………………………………………………

e)a member of the Noble gases………………………………………………………………………...

f) a transition metal in the same period as iron…………………………………………………………

Question 22 (3 marks)

Write balanced chemical equations for the following reactions

a. Calcium carbonate reacts with hydrochloric acid to produce a salt, water and carbon dioxide 1

……………………………………………………………………………………………………………

b. Zinc reacts with copper (II) sulfate to form copper metal and zinc sulfate1

……………………………………………………………………………………………………………

c. Reaction of magnesium with sulfuric acid will produce a salt and a gas1

……………………………………………………………………………………………………………

Question 23 (6 marks)

a. Write a balanced equation to show the electrolysis of water. (Include states) 1

……………………………………………………………………………………………………………

b. Is electrolysis of water a chemical or physical change. Justify your answer 2

……………………………………………………………………………………………………………

c. Compare the molecular changes that take place during the electrolysisof water with those that 3

occurduring the boiling of water. Include one diagram to illustrate your answer

……………………………………………………………………………………………………………