topic 3 chemical formulae and equation

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TOPIC 3: CHEMICAL FORMULAE AND EQUATIONS 1 The molecular formula of butanoic acid is C 3 H 7 COOH. Calculate the relative molecular mass of butanoic acid. Formula molekul bagi asid butanoik ialah C 3 H 7 COOH. Hitungkan jisim molekul relatif bagi asid butanoik.. [Relative atomic mass of H = 1, C = 12, O = 16] [Jisim atom relatif H = 1, C = 12, O = 16] A B C D 58 68 88 98 2 The table shows the relative atomic masses of nitrogen and oxygen. Jadual menunjukkan jisim atom bagi unsur nitrogen dan oksigen. . Element Unsur Relative Atomic Mass Jisim atom relatif Nitrogen, N Nitrogen, N 14 Oxygen,O Oksigen, O 16 Nitrogen and oxygen react to form nitrogen dioxide gas. What is the relative molecular mass of nitrogen dioxide gas? Nitrogen dan oksigen bertindak balas untuk membentuk gas nitrogen dioksida.. Apakah jisim molekul relatif bagi gas nitrogen dioksida? A 30 B 44 C 46

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Page 1: Topic 3 Chemical Formulae and Equation

TOPIC 3: CHEMICAL FORMULAE AND EQUATIONS

1 The molecular formula of butanoic acid is C3H7COOH. Calculate the relative molecular mass of butanoic acid.Formula molekul bagi asid butanoik ialah C3H7COOH. Hitungkan jisim molekul relatif bagi asid butanoik..

[Relative atomic mass of H = 1, C = 12, O = 16][Jisim atom relatif H = 1, C = 12, O = 16]

A

B

C

D

58

68

88

98

2 The table shows the relative atomic masses of nitrogen and oxygen. Jadual menunjukkan jisim atom bagi unsur nitrogen dan oksigen. .

ElementUnsur

Relative Atomic MassJisim atom relatif

Nitrogen, NNitrogen, N

14

Oxygen,OOksigen, O

16

Nitrogen and oxygen react to form nitrogen dioxide gas.What is the relative molecular mass of nitrogen dioxide gas?Nitrogen dan oksigen bertindak balas untuk membentuk gas nitrogen dioksida..

Apakah jisim molekul relatif bagi gas nitrogen dioksida?

A 30B 44C 46D 92

3 What is the relative molecular mass of ammonium sulphate, (NH4)2SO4?

Apakah jisim molekul relatif bagi ammonium sulfat, (NH4)2SO4?[Relative atomic mass: H = 1, N = 14, O = 16, S = 32]

A.114 B.116 C.118 D.1324. How many times are one atom of bromine heavier than one atom of calcium?

[Relative atomic mass: Ca, 40; Br, 80]

Page 2: Topic 3 Chemical Formulae and Equation

Berapa kali satu atom bromin lebih berat daripada satu atom kalsium?[Jisim atom relatif: Ca, 40; Br, 80]A 0.2B 0.5C 2.0D 5.0

5. Which of the following amount of substances contains the same number of atom as in 0.72 g of magnesium?

[The relative atomic mass of H=1, C=12, O=16, Mg=24, Ca=40, Avogadro constant = 6.0 X 1023 mol-1]A 0.06 g hydrogen gasB 0.12 g calciumC 0.48 g oxygen gasD 0.69 g carbon

6 Table shows the relative atomic mass of elements Q and T.Jadual menunjukkan jisim atom relative bagi unsur Q dan unsur T.

ElementUnsur

Relative atomic massJisim atom relatif

Q 32T 64

Which of the following is true about the atoms of elements Q and T ?Antara berikut, yang manakah benar tentang atom bagi unsure Q dan unsur T? A The mass of one atom of Q is 32 g

Jisim satu atom Q ialah 32g

B The number of protons in atom T is 64Bilangan proton dalam atom T ialah 64

C 1 mole of Q has the same mass as 1 mole of T1 mol Q mempunyai jisim yang sama dengan 1 mol T

D 2moles of Q have the same mass as 1 mole of T2 mol Q mempunyai jisim yang sama dengan 1 mol T

7.Table 6 shows the relative atomic mass of elements X and Y.

Element Relative atomic mass

Page 3: Topic 3 Chemical Formulae and Equation

X 16Y 64

TABLE 6Which of the following is true about the atoms of elements X and Y?

A The mass of one atom of X is 16 gB The number of protons in atom Y is 64C 4 moles of X have the same mass as 1 mole of YD 2 atoms of Y is four times heavier than one atom of X

8.Which of the following is the number of molecules in 1 mole of carbon dioxide, CO2?[Avogadro constant = 6.0 X 1023 mol-1]

A 1.5 X 1023 moleculesB 6.0 X 1023 moleculesC 1.2 X 1024 moleculesD 2.4 X 1024 molecules

9. What is the number of molecules in 32 g of oxygen gas ? Apakah bilangan molekul dalam 32 g gas oksigen? [ Relative atomic mass of O = 16 and Avogadro’s Constant is 6 x 10 23 mol -1 ]

[ Jisim atom relatif bagi O = 16 dan Pemalar Avogadro ialah 6 x 10 23 mol -1] A 6.0 x 10 23

B 1.2 x 10 24

C 9.6 x 10 24

D 1.9 x 10 25

10 What is the percentage of nitrogen by mass in ammonium nitrate, NH4NO3? Apakah peratus nitrogen dalam ammonium nitrat NH4NO3 mengikut jisim?

[ Relative atomic mass:H= 1, N = 14 ,O= 16][ Jisim atom relatif : H= 1, N = 14, O= 16]

A 3.50 %

B 8.75 %

C 17.50 %

D 35.00 %

11 Which of the following has the most number of atoms?Antara berikut, yang manakah mempunyai bilangan atom yang paling banyak?

Page 4: Topic 3 Chemical Formulae and Equation

H2

[Relative atomic mass: H, 1; C, 12; O, 16; S, 32] [Jisim atom relatif: H, 1; C, 12; O, 16; S, 32]

A 2.0 g of hydrogen2.0 g hidrogen

B 18.0 g of carbon18.0 g karbon

C 30.0 g of oxygen30.0 g oksigen

D 62.0 g of sulphur62.0 g sulfur

12 Diagram 5 shows a part of set up apparatus to determine the empirical formula of metal oxide.Rajah 5 menunjukkan sebahagian dari radas untuk mengenalpasti formula empiriks bagi oksida logam.

Diagram 5 Rajah 5

Which of the metal oxide cannot be used by this method?Oksida logam yang manakah tidak boleh ditentukan menggunakan kaedah ini.?

A Zinc oxideZink oksida

B Lead(II) oxidePlumbum(II) oksida

C Copper(II) oxideKuprum(II) oksida

D Iron(III) oxideFerum(II) oksida

13 3.1 g metal oxide M contains 2.3 g of metal M. Determine the emperical formula of metal oxide M.3.1 g oksida logam M mengandungi 2.3 g logam M.Tentukan formula empirik bagi oksida logam M.

[Relative atomic mass of M = 23, O = 16][Jisim atom relatif M = 23, O = 16]

A

B

C

D

MO

M2O

MO2

M2O2

Page 5: Topic 3 Chemical Formulae and Equation

H2

14. Diagram 5 shows a part of set up apparatus to determine the empirical formula of metal oxide.Rajah 5 menunjukkan sebahagian dari radas untuk mengenalpasti formula empiriks bagi oksida logam.

Diagram 5 Rajah 5

Which of the metal oxide cannot be used by this method?Oksida logam yang manakah tidak boleh ditentukan menggunakan kaedah ini.?

A Zinc oxideZink oksida

B Lead(II) oxidePlumbum(II) oksida

C Copper(II) oxideKuprum(II) oksida

D Iron(III) oxideFerum(II) oksida

15. 9.75 g of element X reacted with 63.5 g of element Y to form a compound with the formula XY2.What is the relative atomic mass of element X?.[Given that the relative atomic mass of Y=127]9.25 g unsur X bertindak balas dengan 63.5 g unsur Y untuk membentuk satu sebatian yang mempunyai formula XY2.Berapakah jisim atom relatif unsur X?[Diberi jisim atom relatif Y=127]

A 23

B 39

C 40

D 88

16 3.12 g of metal J reacts with o.64 g of oxygen to form a compound with the empirical formula J2O.What is the relative atomic mass of metal J?[Relative atomic mass of O = 16 ]

Apakah jisim atom relatif logam J? [Jisim atom relative O = 16 ]

A

B

39

55

Page 6: Topic 3 Chemical Formulae and Equation

C

D

78

156

17 2.10 g of element Q combined with 0.80 g of element R to produce a compound with formula Q3R4. What is the relative atomic mass of element Q?2.10 g unsur Q berpadu dengan 0.80 g unsur R untuk menghasilkan sebatiandengan formula Q3R4. Berapakah jisim atom relatif unsur Q?[Relative atomic mass : R = 16]

ABCD

14425658

18.Table 3 shows the mass of carbon and hydrogen in a compound with their respective atomic masses.

Jadual 3 menunjukkan jisim karbon dan hidrogen dalam suatu sebatian dengan jisim atom relatif masing-masing.

ElementUnsur

C H

Mass/gJisim/g

3.6 0.6

Relative atomic massJisim atom relatif

12 1

Table 3 Jadual 3 What is the empirical formula of the compound?

Apakah formula empirik bagi sebatian tersebut?

A CH4

B CH3

C CH2

D CH

19. 7 g of hydrocarbon contains 1 g of hydrogen. Which of the following molecular formulae most probably represent represent the hydrocarbon?

[Relative atomic mass, H=1; C=12] 7 g suatu hidrokarbon mengandungi 1 g hidrogen. Antara formula molekul berikut, yang manakah mungkin mewakili hidrokarbon tersebut?

[Jisim atom relatif; H=1; C=12]

I C3H6

II C5H12

III C4H8

IV C6H6

A II sahaja C II dan IV sahajaB I dan III sahaja D I, III dan IV sahaja

20. 1.72 g of an oxide of metal X contains 0.8 g oxygen. What is the empirical formula of the oxide?1.72 g oksida logam X mengandungi 0.8 g oksigen. Apakah formula empirik bagi oksida itu?

Page 7: Topic 3 Chemical Formulae and Equation

[Relative atomic mass : X = 46 ; O = 16]

ABCD

XO2

X2OX2O3

X2O5

21.Table 5 shows the mass and the relative atomic mass of elements M and oxygen.

Element M OMass/g 2.7 2.4

Relative atomic mass 27 16TABLE 5

Which of the following is the empirical formula of oxide of M?A MOB MO2

C M2OD M2O3

22 Molecular formula of butene is C4H8. What is the empirical formula of butene?Formula molekul butena ialah C4H8 Apakah formula empirik butena?A

B

C

D

CH

CH2

CnH2n

(CH2)n

23. Given the formulae for aluminium ion is Al3+ and sulphate ion is SO42- . Choose the correct

chemical formula of alumminium sulphate. Diberi formula ion aluminium ialah Al3+ dan ion sulfat ialah SO4

2- . Pilih formula kimia yang betul bagi aluminium sulfat.

A Al(SO4)3

B Al2(SO4)3

C Al3(SO4)2

D AlSO4

24 An atom of element M has 4 shells containing electrons.When element M reacts with chlorine, a compound with the formula MCl is formed.Which of the following is element M?Given that the proton number of Na =11, Si =14, K =19 Ca =20

Atom unsur M mempunyai 4 petala berisi elektron.Apabila unsur M bertindak balas dengan gas klorin, sebatian berformula MCl terbentuk.Antara berikut, yang manakah unsur M?Diberi nombor proton Na =11, Si =14, K =19 Ca =20

A CalciumKalsium

Page 8: Topic 3 Chemical Formulae and Equation

B SodiumNatrium

C SiliconeSilikon

D PotassiumKalium

25 The formula for a sulphate ion is SO42- and for a nitrate is NO3

-

If the formula of the sulphate salt of T is TSO4, what is the formula of nitrate salt of T?Formula bagi ion sulfat ialah SO4

2- dan ion nitrat ialah NO3-

Jika formula garam sulfat bagi T ialah TSO4, apakah formula garam nitrat bagi T?

A

B

C

D

TNO3

T2NO3

T(NO3)2

T(NO3)3

26 Which of the following chemical formulae is correct?Antara berikut, yang manakah formula kimia yang betul? A

B

C

D

Cu2Cl

AlCl3

NaO2

BaOH

27 The following is chemical equation for a reaction.Berikut ialah persamaan kimia bagi satu tindak balas.

CaCO3 + 2HNO3 Ca(NO3)2 + H2O + CO2

Which of the following are reactants?Antara berikut, yang manakah bahan tindak balas? A

B

C

D

H2O and CO2

HNO3 and CO2

CaCO3 and HNO3

Ca(NO3)2, H2O and CO2

28 Given the formulae for aluminium ion is Al3+ and sulphate ion is SO42- . Choose the correct

chemical formula of alumminium sulphate.Diberi formula ion aluminium ialah Al3+ dan ion sulfat ialah SO4

2- . Pilih formula kimia yang

Page 9: Topic 3 Chemical Formulae and Equation

betul bagi aluminium sulfat.

A Al(SO4)3

B Al2(SO4)3

C Al3(SO4)2

D AlSO4

29 The equation shows the reaction between V and W,

Persamaan menunjukkan tindak balas antara V dan W

V + 2W X + Y

Which of the following statements is true?Antara pernyataan berikut manakah benar? A V and W are the products of the reaction

V dan W adalah hasil tindak balas

B X and Y are the reactants of the reactionX dan Y adalah bahan tindak balas

C 1 mole of V react with 1 mole of W to produce 1 mole of X and 1 mole of Y1 mol V bertindak balas dengan 1 mol W menghasilkan 1 mol X dan 1 mol Y

D 1 mole of V react with 2 moles of W to produce 1 mole of X and 1 mole of Y1 mol V bertindak balas dengan 2 mol W menghasilkan 1 mol X dan 1

mol Y

30. The following equation shows the decomposition of copper(II) carbonate when heated strongly.

Persamaan berikut menunjukkan penguraian kuprum(II) karbonat apabila dipanaskan dengan kuat.

CuCO3 CuO + CO2

What is the mass of copper(II) oxide produced when 12.4 g of copper(II) carbonate is decomposed completely?[Relative atomic mass: C, 12; O, 16; Cu, 64]Apakah jisim kuprum(II) oksida yang terhasil apabila 12.4 g kuprum(II) karbonat terurai dengan lengkap?[Jisim atom relatif: C, 12; O, 16; Cu, 64]

A 4.0 gB 8.0 gC 12.4 gD 80.0 g

31. An advertising light is filled with 1800 cm3 of neon gas at room condition. Calculate the number of neon atom in the light?[1 mol gas occupies the volume of 24 dm3 at room temperature and pressure, Avogadro Numbers = 6.02 x 1023]

Page 10: Topic 3 Chemical Formulae and Equation

Sebiji lampu iklan telah diisi dengan 1800 cm3 gas neon pada keadaan bilik. Hitung bilangan atom bagi gas neon dalam lampu itu?[1 mol gas menepati isipadu sebanyak 24 dm3 pada suhu dan tekanan bilik, nombor avogardo = 6.02 x 1023]A 4.515 x 1022

B 4.515 x 1023

C 8.03 x 1022

D 8.03 x 1021

32. The following equation shows the decomposition reaction of lead(II) nitrate when heated at

room temperature and pressure.Persamaan berikut menunjukkan tindak balas penguraian plumbum(II) nitrat apabila dipanaskan pada suhu dan tekanan bilik.

2 Pb(NO3)2 2PbO + 4 NO2 + O2

Which of the following is true when 0.1 mol of lead(II) nitrate is decomposed?[Relative atomic mass: N=14, O=16,Pb=207 and 1 mol gas occupies the volume of 24 dm3 at room temperature and pressure]Antara yang berikut, yang manakah benar apabila 1 mol plumbum(II) nitrat terurai?[Jisim atom relatif: N=14, O=16,Pb=207 dan 1 mol gas menepati isipadu sebanyak 24 dm3 pada suhu dan tekanan bilik.]

A 44.6 g of lead(II) oxide is formed. 44.6 g plumbum(II) oksida terbentuk.

B 4800 cm3 of nitrogen dioxide is given off. 4800 cm3 gas nitrogen dioksida terbebas

C 2.4 dm3 of oxygen gases is given off.2.4 dm3 gas oksigen terbebas.

D 4.46 g of lead(II) oxide is formed.4.46 g plumbum(II) oksida terbentuk.

Trial kedah 2009Topic 3: CHEMICAL EQUATIONS AND FORMULAETrial kedah 200933 An advertising light is filled with 1800 cm3 of neon gas at room condition. Calculate the

number of neon atom in the light?[1 mol gas occupies the volume of 24 dm3 at room temperature and pressure, Avogadro Numbers = 6.02 x 1023]Sebiji lampu iklan telah diisi dengan 1800 cm3 gas neon pada keadaan bilik. Hitung bilangan atom bagi gas neon dalam lampu itu?[1 mol gas menepati isipadu sebanyak 24 dm3 pada suhu dan tekanan bilik, nombor avogardo = 6.02 x 1023]

A 4.515 x 1022

B 4.515 x 1023

Page 11: Topic 3 Chemical Formulae and Equation

C 8.03 x 1022

D 8.03 x 1021

34. Oxygen exists as diatomic molecule. What is the mass of one oxygen molecule?[Relative atomic mass of O=16;Avogadro number = 6.02 X 1023 mol-1]

A 1.6 X 10-23 gB 2.7 X 10-23 gC 3.2 X 10-23 gD 5.3 X 10-23 g

35.A compound with the formula of X2SO4 has a relative formula mass of 174. What is the relative atomic mass of X?

[Relative atomic mass of S=32, O=16]

A 23B 24C 39D 40

36 When copper(II) carbonate is heated , it decomposes to copper(II) oxide and carbon dioxide gas. The equation for the reaction is Apabila kuprum(II) karbonat dipanaskan, ia akan terurai kepada kuprum(II)oksida dan gas karbon dioksida. Persamaan bagi tindak balas ini adalah

CuCO3 (s) CuO (s) + CO2 ( g)

12.4 g of of copper(II) carbonate decomposes completely. What is the mass of copper(II) oxide formed ? 12.4 g kuprum(II) karbonat terurai dengan lengkap. Apakah jisim kuprum(II) oksida yang terbentuk?

[ Relative atomic mass : Cu=64, O=16, C=12 ] [ Jisim atom relatif : Cu=64, O=16, C=12 ]

A 4.4 gB 8.0 gC 44.0 gD 80.0 g

37 Hydrogen peroxide decomposes according to the following equation:Hidrogen peroksida terurai mengikut persamaan berikut:

2 H2O2 2 H2O + O2

One mole of hydrogen peroxide is decomposed.What is the volume of oxygen gas released?Satu mol hidrogen peroksida telah terurai. Apakah isipadu gas oksigen yang dibebaskan?

[1 mol of gas occupies 24 dm 3 at room temperature and pressure ]

Page 12: Topic 3 Chemical Formulae and Equation

[1 mol gas menempati 24 dm 3 pada suhu dan tekanan bilik ]

A 96 dm 3

B 48 dm 3

C 24 dm 3

D 12 dm 3

1. Table 2 shows proton number and nucleon number for atoms P, Q and R.Jadual 1 menunjukkan nombor proton dan nombor nukleon bagi atom-atom P, Q dan R.

AtomAtom

Proton numberNombor Proton

Nucleon numberNombor nukleon

P 11 23

Q 17 35

R 17 37

Table 2Jadual 2

Page 13: Topic 3 Chemical Formulae and Equation

(a) What is meant by the nucleon number of an atom?Apakah yang dimaksudkan dengan nombor nukleon bagi atom?

……………………………………………………………………………………………………..

[1 mark]

(b) (i) State the atoms that are isotopes. Nyatakan atom-atom yang merupakan isotop.

.......…………………………………………………………………………………………..

[1 mark]

(ii) State a reason for your answer in (b)(i).Nyatakan sebab bagi jawapan anda di (b)(i).

...................................................................................................................................

...................................................................................................................................[1 mark]

(c) Write the electron arrangement of atom P. Tuliskan susunan elektron bagi atom P.

.........……………………………………………………………………………………....…

[1 mark]

(d) Draw the electron arrangement of ion Q. Lukiskan susunan elektron bagi ion Q.

[2 marks]

Page 14: Topic 3 Chemical Formulae and Equation

(e) The information shows the composition of an organic compound S. Maklumat menunjukkan komposisi suatu sebatian organik S.

Determine the empirical formula of compound S.Tentukan formula empirik bagi sebatian S.

2 Diagram 4.1 shows the set up of apparatus for an experiment to determine the empirical formula of magnesium oxide.Rajah 4.1 menunjukkan susunan radas bagi suatu eksperimen untuk menentukan formula empirik magnesium oksida.

Diagram 4.1 Rajah 4.1

(a) What is the meaning of empirical formula?

Carbon - 64.87% Karbon

Hydrogen - 13.51% Hidrogen

Oxygen - 21.62% Oksigen

[Relative atomic mass : H=1, C=12, O=16] Jisim atom relatif

Page 15: Topic 3 Chemical Formulae and Equation

Apakah maksud formula empirik?

[1 mark] [1 markah]

(b) Diagram 4.2 shows the results of the experiment.Rajah 4.2 menunjukkan keputusan experiment itu.

Mass of crucible + lid = 24.88 g Jisim mangkuk pijar + penutup

Mass of crucible + lid + magnesium ribbon = 25.12 g Jisim mangkuk pijar + penutup + pita magnesium

Mass of crucible + lid + magnesium oxide = 25.28 g Jisim mangkuk pijar + penutup + magnesium oksida

Diagram 4.2 Rajah 4.2

(i) Based on Diagram 4.2, complete Table 4 and determine the empirical formula of magnesium oxide.Berdasarkan Rajah 4.2, lengkapkan Jadual 4 dan seterusnya tentukan formula empirik bagi magnesium oksida:[Relative atomic mass: O = 16, Mg = 24][Jisim atom relatif: O = 16, Mg = 24]

ElementUnsur

Mg O

Mass (g)JisimNumber of molesBilangan molSimplest ratio of molesNisbah ringkas bilangan molEmpirical formula Formula empiric

Table 4Jadual 4

[6 marks] [6 markah]

(ii) Write the chemical equation for the reaction in the experiment.Tuliskan persamaan kimia bagi tindak balas dalam eksperimen itu.

Page 16: Topic 3 Chemical Formulae and Equation

[1 mark] [1 markah]

(c) Why the process of heating, cooling and weighing are repeated until a constant mass is obtained?Mengapakah proses pemanasan, penyejukan dan penimbangan diulang sehingga jisim yang tetap diperolehi?

[1 mark] [1 markah]

(d) Why this experiment is not suitable to be used to determine the empirical formula of copper(II) oxide? Mengapakah eksperimen ini tidak sesuai digunakan untuk menentukan formula empirik kuprum(II) oksida?

[1 marks] [1markah]

Page 17: Topic 3 Chemical Formulae and Equation
Page 18: Topic 3 Chemical Formulae and Equation
Page 19: Topic 3 Chemical Formulae and Equation

ESSAY

1. (a) The figure below shows the standard representation for an atom of element Na

State three types of information that can be deduced ? Draw the electron arrangement for an atom of element Na

[6 marks]

(b) The following figure shows the empirical formula of glucose :

(i) What is the meaning of empirical formula ? (ii) The relative molecular mass of glucose is 180, determine the molecular formula of glucose

[4 marks]

(c) (i) A chloride of iron contains 2.80 g of iron and 5.32 g of chlorine. Determine the empirical formula of the compound. [ Relative atomic mass : Fe = 56 , Cl = 35.5 ] [4 marks] (ii) Write a chemical equation to represent the reaction between iron and chlorine. Calculate the volume of chlorine gas that react completely with 2.80 g iron. [ 1 mole of gas occupied 24 dm3 at room temperature and pressure ] [6 marks]

Page 20: Topic 3 Chemical Formulae and Equation

9 (a)

(b)

By using suitable example, explain what are meant by empirical formula and molecular formula.Dengan menggunakan contoh yang sesuai, terangkan apa yang dimaksudkan dengan formula empirik dan formula molekul.

[3 marks]

The information below is for compound QMaklumat berikut adalah bagi sebatian Q.

Based on the information of compound Q, determine:Berdasarkan maklumat bagi sebatian Q, tentukan:

(i) The empirical formulaFormula empiriknya

(ii) The molecular formulaFormula molekulnya[ Relative atomic mass: C,12; H,1; O,16][ Jisim atom relatif: C,12; H,1; O,16]

[ 5 marks]

Carbon 40.00% Karbon Hydrogen 6.66% Hidrogen Oxygen 53.33%

Oksigen

Relative molecular mass 180Jisim molekul relatif

Page 21: Topic 3 Chemical Formulae and Equation

Heat / panaskan

Asbestos paperKertas

asbestos

Metal oxide / Oksida logam

Heat / panaskan

Dry hydrogen gas / Gas Hidrogen kering

(c) Diagram 9 shows the set-up of apparatus to determine the empirical formula of two different compounds.Rajah 9 menunjukkan susunan radas bagi menentukan formula empirik dua sebatian yang berlainan.

Method IKaedah I

Method IIKaedah II

MetalLogam

Table 9Rajah 9

(i) Explain why method II is not suitable to determine the empirical formula of magnesium oxide?Terangkan mengapa kaedah II tidak sesuai bagi menentukan formula empirik bagi magnesium oksida?

[1mark](ii) Suggest one metal oxide in method II.

Cadangkan satu oksida logam dalam kaedah II.[1 mark]

(iii) Using a suitable example, describe a laboratory experiment to determine the empirical formula of an oxide of a reactive metal. Your explanation should include:Dengan menggunakan contoh yang sesuai, huraikan suatu eksperimen di makmal untuk menentukan formula empirik bagi suatu oksida logam reaktif.. Penerangan anda mestilah meliputi :

Procedure of the experimentProsedur bagi eksperimen

Tabulation of dataPenjadualan data

[10 marks]

Page 22: Topic 3 Chemical Formulae and Equation