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21Which diagram below represents an incomplete reaction between the elements nitrogen gas and hydrogen gas?

ABCD

22Phosphonium carbonate is a compound with the chemical formula, (PH4)2CO3. How many different elements are present in phosphonium carbonate?

A2C4

B3D5

23Nippon paint for wood consists of resins, thinner (a volatile liquid that does not mix with water) and dyes. Once applied, wood paint hardens as the thinner in it evaporates.

Which of the following statements is true?

AWood paint boils over a range of temperatures because it is a mixture.

BIn wood paint, the thinner, resins and dyes are always combined in a fixed proportion as it is a mixture.

CWood paint is an element.

DWood paint is a compound because its components can be separated by the process of evaporation to dryness.

24Emily accidently tripped and dropped his bag of table salt onto a sandy beach. The bag is made of paper and the table salt is firmly sealed inside the paper bag with aluminium staples. The fall causes the paper bag to burst and the spilled table salt is mixed with sand. Which of the following is an element?

Aaluminium staplesCpaper bag

Btable saltDsand along the beach

25A colourless substance, W has a fixed melting point and a fixed boiling point. W can be classified as

1 an element

2 a pure compound

3 a mixture

A1 onlyC3 only

B2 onlyD1 and 2

26In the nucleus of an atom, which sub-atomic particles can be found?

Aelectrons and protons Cprotons and neutrons

Belectrons and neutronsDprotons, neutrons and electrons

27How many neutrons are there in an atom of calcium, 20 Ca ?

A20C42

B22D62

28The graph below shows how a number changes for the elements from oxygen to magnesium.

What is this number represented along the Y axis?

Athe nucleon number of an atom

Bthe number of neutrons in an atom

Cthe number of electrons in an atom

Dthe number of valence electrons

29An ion of Z contains 3 protons, 4 neutrons and 2 electrons. Which symbol correctly represents the atom of Z?

A3 ZC2 Z

B4 ZD3 Z

30The electronic structure of atoms X and Y are shown.

X reacts with Y to form an ionic compound with the formula

AXY2 .CX2Y2 .

BX2Y .DXY .

31Which process changes a sodium atom, Na into a sodium ion, Na+?

Athe gain of one electronCthe gain of one proton

Bthe loss of one electronDthe loss of one proton

32The table compares the properties of ammonia gas, NH3 and magnesium oxide, MgO. Which property is matched wrongly?

ammonia gasmagnesium oxide

AIt does not conduct electricity.It conducts electricity when molten.

BIt is a gas.It is a solid.

CIt has a low melting point.It has a high melting point.

DIt is an ionic compound.It is a simple covalent molecule.

33The Avogadros constant is the number of

Aatoms in 1 g of nitrogen gas.

Bmolecules in 16 g of oxygen gas.

Catoms in exactly 2 g of helium.

Datoms in exactly 12 g of carbon-12.

34How many moles are there in 15.5 g of sodium oxide, Na2O?

A0.125 molC0.5 mol

B0.25 molD1.0 mol

35The equation for the complete combustion of propene is

2C3H6(g) + 9O2(g) 6CO2(g) + 6H2O(g)

This equation shows that

Atwo molecules of propene combine with nine moles of oxygen.

Bsix molecules of steam can be obtained from two moles of propene.

Csix moles of carbon dioxide are produced from nine moles of oxygen gas.

D42 g of propene combine with 32 g of oxygen.

36What is the mass of 1200 cm3 of carbon dioxide at r.t.p.?

A1.2 gC24 g

B2.2 gD52.8 g

37Which statement is true for alkalis?

AThey produce hydroxide ions when dissolved in water.

BThey react with zinc to produce carbon dioxide.

CThey react with acids to give hydrogen gas.

DThey react with carbonates to give a salt, carbon dioxide and water.

38Which of the following statements is true for dilute hydrochloric acid and nitric acid?

AThey react with calcium carbonate to give carbon dioxide.

BThey react with copper to give hydrogen gas.

CThey turn red litmus paper blue.

DSalt and water are formed when they react together.

39An oxide, M, reacts with both dilute sulfuric acid and potassium hydroxide solution to form a salt and water. What type of oxide is M?

AacidicCBasic

BamphotericDneutral

40Which substance is not used to prepare magnesium nitrate by reaction with nitric acid?

Amagnesium carbonateCmagnesium chloride

Bmagnesium hydroxideDmagnesium oxide

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________________________________________________________________________________________________Canberra Secondary School5076 Science (Physics/Chemistry) Paper 12015 Semestral Assessment 1 Secondary 3 Express