topic 7 acids and bases

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TOPIC 7: ACIDS AND BASES 9 Which of the following is true about weak alkali? Antara berikut yang manakah benar tentang alkali lemah? A The pH value is more than 7 Mempunyai pH lebih daripada 7 B Unable to neutralize acid Tidak boleh meneutralkan acid C Change blue litmus paper to red Menukarkan kertas litmus biru ke merah D Ionizes partially in water to produce hydroxide ions Mengion separa dalam air menghasilkan ion hidroksida 1. Which of the following solution has the lowest pH value? Antara larutan berikut, yang manakah mempunyai nilai pH paling rendah? A Ethanoic acid 0.1 mol dm -3 Asid etanoik 0.1 mol dm -3 B Hydrochloric acid 0.1 mol dm -3 Asid hidroklorik 0.1 mol dm -3 C Ammonia solution 0.1 mol dm -3 Larutan ammonia 0.1 mol dm -3 D Sodium hydroxide solution 0.1 mol dm -3 Larutan natrium hidroksida 0.1 mol dm -3 The following equation shows the reaction between hydrochloric acid and sodium hydroxide solution. Persamaan berikut menunjukkan tindak balas antara asid hidroklorik dengan larutan natrium hidroksida. HCl + NaOH NaCl + H 2 O What is the volume of 1.0 mol dm -3 of sodium hydroxide solution required to neutralise 25 cm 3 of 1.0 mol dm -3 of hydrochloric acid? Apakah isipadu larutan natrium hidroksida 1.0 mol dm -3 yang diperlukan untuk meneutralkan 25 cm 3 asid hidroklorik 1.0 mol dm -3 ? A 12.5 cm 3 B 25.0 cm 3 C 40.0 cm 3 D 50.0 cm 3 2 Which of the following acids is a weak acid?

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TOPIC 7: ACIDS AND BASES9Which of the following is true about weak alkali?Antara berikut yang manakah benar tentang alkali lemah?

A

The pH value is more than 7Mempunyai pH lebih daripada 7

BUnable to neutralize acidTidak boleh meneutralkan acid

CChange blue litmus paper to redMenukarkan kertas litmus biru ke merah

DIonizes partially in water to produce hydroxide ionsMengion separa dalam air menghasilkan ion hidroksida

1. Which of the following solution has the lowest pH value?Antara larutan berikut, yang manakah mempunyai nilai pH paling rendah?

AEthanoic acid 0.1 mol dm-3Asid etanoik 0.1 mol dm-3BHydrochloric acid 0.1 mol dm-3Asid hidroklorik 0.1 mol dm-3CAmmonia solution 0.1 mol dm-3Larutan ammonia 0.1 mol dm-3DSodium hydroxide solution 0.1 mol dm-3Larutan natrium hidroksida 0.1 mol dm-3

The following equation shows the reaction between hydrochloric acid and sodium hydroxide solution. Persamaan berikut menunjukkan tindak balas antara asid hidroklorik dengan larutan natrium hidroksida.

HCl + NaOH NaCl + H2O

What is the volume of 1.0 mol dm-3 of sodium hydroxide solution required to neutralise 25 cm3 of 1.0 mol dm-3 of hydrochloric acid?Apakah isipadu larutan natrium hidroksida 1.0 mol dm-3 yang diperlukan untuk meneutralkan 25 cm3 asid hidroklorik 1.0 mol dm-3 ?

A12.5 cm3B25.0 cm3C40.0 cm3D50.0 cm3

2Which of the following acids is a weak acid?Antara asid berikut, yang manakah merupakan asid lemah?

ABCDHydrochloric acidEthanoic acidSulphuric acidNitric acid

47Diagram 15 shows the set up of apparatus for the titration of potassium hydroxide solution with sulphuric acid.Rajah 15 menunjukkan susunan radas bagi pentitratan larutan kalium hidroksida dengan asid sulfurik.

20 cm3 of 0.1 mol dm-3 potassium hydroxide solution20 cm3 larutan kalium hidroksida 0.1 mol dm-3 mol dm-3 of sulphuric acidAsid sulfurik 0.1 mol dm-3

Diagram 15Rajah 15

What is the total volume of the mixture in the conical flask at the end point ?Apakah jumlah isipadu campuran di dalam kelalang kon pada takat akhir ? A10 cm3B20 cm3C30 cm3D40 cm3

1. The sting of jelly-fish is alkaline and causes pain.Which of the following substances is the most suitable to be used to treat the pain?

Sengatan obor-obor adalah beralkali dan menyebabkan kesakitan.Antara bahan berikut, manakah yang paling sesuai digunakan untuk merawat kesakitan tersebut?

AFlourTepung BVinegarCukaCCooking oilMinyak masak DBaking powderSerbuk penaik7Which solution shows the highest pH value?Larutan manakah menunjukkan nilai pH tertinggi?

A0.5 mol dm-3 sulphuric acid 0.5 mol dm-3 acid sulfurik

B0.5 mol dm-3 ethanoic acid .0.5 mol dm-3 asid etanoik .

C0.5 mol dm-3 aqueous ammonia0.5 mol dm-3 ammonia akueous

D0.5 mol dm-3 sodium hydroxide solution 0.5 mol dm-3 larutan natrium hidroksida

7Which solution shows the highest pH value?Larutan manakah menunjukkan nilai pH tertinggi?

A0.5 mol dm-3 sulphuric acid 0.5 mol dm-3 acid sulfurik

B0.5 mol dm-3 ethanoic acid .0.5 mol dm-3 asid etanoik .

C0.5 mol dm-3 aqueous ammonia0.5 mol dm-3 ammonia akueous

D0.5 mol dm-3 sodium hydroxide solution 0.5 mol dm-3 larutan natrium hidroksida

28Which of the following statement correctly describes a strong alkali? Antara pernyataan berikut, yang manakah betul tentang alkali kuat ?

IHas a low pH value Nilai pH yang rendah

IIIonises completely in waterMengion dengan lengkap dalam air

IIIHas a high concentration of hydroxide ionsMempunyai kepekatan ion hidroksida yang tinggi

IVExist as molecules in waterWujud sebagai molekul dalam air

AI and II I dan II

BI and IVI dan 1V

CII and III II dan III

DIII and IVIII dan IV

44The equation shows the reaction between sulphuric acid and potassium hydroxide. Persamaan menunjukkan tindakbalas di antara asid sulfurik dan kalium hidroksida.

H2SO4 + 2KOH K2SO4 + 2H2O

What is the volume of 1.0 mol dm-3 potassium hydroxide solution which can neutralise 25.0 cm3 of 1.0 mol dm-3 sulphuric acid? Berapakah isipadu 1.0 mol dm-3 larutan kalium hidroksida yang boleh meneutralkan 25.0 cm3 1.0 moldm-3 asid sulfurik ?

A12.5 cm3

B25.0 cm3

C50.0 cm3

D70.0 cm3

6Which of the following is a weak acid?Asid yang manakah asid lemah?

ANitric acidAsid nitrikBEthanoic acidAsid etanoik CSulphuric acidAsid sulfurikDHydrochloric acidAsid hidroklorik47Which of the following acidic solutions contains the highest number of hydrogen ions?Antara larutan asid berikut yang manakah mempunyai bilangan ion hydrogen yang paling tinggi?

A

B

C

D100 cm3 hydrochloric acid 0.1 mol dm-3100 cm3 asid hidroklorik 0.1 mol dm-3

50 cm3 sulphuric acid 0.2 mol dm-350 cm3 asid sulfurik 0.2 mol dm-3

100 cm3 ethanoic acid 0.2 mol dm-3100 cm3 asid etanoik 0.2 mol dm-3100 cm3 nitric acid 0.1 mol dm-3100 cm3 asid nitrik 0.1 mol dm-3

TOPIC 7:ACID AND BASESTrial kedah 200940A beaker contains 100 cm3 of 0.5 mol dm-3 sodium hydroxide solution. Calculate the number of moles of sodium hydroxide in the beaker.Sebuah bikar mengandungi 100 cm3 larutan natrium hidroksida 0.5 mol dm-3. Hitung bilangan mol bagi natrium hidroksida dalam bikar.

ABCD0.050.505.0050.0

41The following equation represents the reaction between hydrochloric acid and sodium hydroxide.Berikut ialah persamaan yang mewakili tindak balas antara asid hidroklorik dan natrium hidroksida.NaOH + HCl NaCl + H2O

What is the mass of sodium chloride formed when 100 cm3 of 0.5 mol dm-3 hydrochloric acid reacts with excess sodium hydroxide solution?Apakah jisim natrium klorida yang terbentuk apabila 100 cm3 asid hidroklorik 0.5 mol dm-3 bertindak balas dengan larutan natrium hidroksida berlebihan?[Relative atomic mass: Na = 23, Cl = 35.5]

27Which of the following solution has the lowest pH value?

AEthanoic acid 0.1 mol dm-3BHydrochloric acid 0.1 mol dm-3CAmmonia solution 0.1 mol dm-3 DSodium hydroxide solution 0.1 mol dm-3

37 The chemical equation shows the reaction between sulphuric acid and potassium hydroxide.

H2SO4 + 2KOH K2SO4 + 2H2O

What is the volume of 0.5 mol dm-3 needed to neutralise 10.0 cm3 of 0.5 mol dm-3 sulphuric acid?

A15.0 cm3B17.5 cm3C20.0 cm3D60.0 cm3

21Which particle is present in glacial ethanoic acid ?Yang manakah wujud dalam asid etanoik glasial ?

AH+

BOH-

CCH3COO-

DCH3COOH

22An aqueous solution of Y has a pH value of 1.Which is true about Y? Larutan akues Y mempunyai nilai pH 1.Yang manakah benar tentang Y?

AY produces a low concentration of H+ ion in waterY menghasilkan kepekatan H+ ion yang rendah di dalam air

BY reacts with an alkali to produce salt and waterY bertindak balas dengan alkali menghasilkan garam dan air

CY turns colourless phenolphthalein to pinkY menukarkan merah jambu fenoltalein kepada tak berwarna

DY ionizes partially in waterY mengion separa di dalam air

23Which ionic equation represents the reaction between sulphuric acid and aqueous sodium hydroxide? Yang manakah ialah persamaan ion yang mewakili tindak balas di antara asid sulfurik dengan natrium hidroksida akues?

AH+ + OH- H2O

BH+ + H2O H3O+

C2Na+ + SO42- Na2SO4

D2NaOH + H2SO4 Na2SO4 + 2H2O

41A farmer discovered that his vegetables were not growing well because the soil was acidic. Which of the following substances can be used to overcome the problem?

Seorang petani mendapati sayurannya tidak tumbuh subur kerana tanahnya berasid. Antara bahan berikut, yang manakah boleh digunakan untuk menyelesaikan masalah tersebut?

A

Zinc oxideZink oksida

BCalcium oxideKalsium oksida

CSodium hydroxideSodium hidroksida

DMagnesium hydroxideMagnesium hidroksida

39Diagram 15 shows the set-up of apparatus for titration of sodium hydroxide solution with sulphuric acid.Rajah 15 menunjukkan susunan radas untuk pentitratan larutan natrium hidroksida dengan asid sulfurik

25 cm3 of 0.2 mol dm-3 natrium hydroxide solution25 cm3 larutan natrium hidroksida 0.2 mol dm-3Sulphuric acid 0.2 mol dm-3Asid sulfurik 0.2 moldm-3 Diagram 15 Rajah 15

What is the volume of sulphuric acid at the end point of the titrationBerapakah isipadu asid sulfurik pada takat akhir pentitratan

A12.5 cm3

B25.0 cm3

C 37.5cm3

D50.0 cm3

1Diagram 1 shows the information about two types of solutions A and B which are used to carry out titration with hydrochloric acid.Rajah 1 menunjukkan maklumat tentang dua jenis larutan A dan B yang digunakan untuk menjalankan pentitratan dengan asid hidroklorik.

Solution A : 50 cm3 of 1.0 mol dm-3 sodium hydroxide, NaOH Larutan A : 50 cm3 natrium hidroksida, NaOH 1.0 mol dm-3 Solution A : 50 cm3 of 1.0 mol dm-3 ammonium hydroxide, NH4OHLarutan B : 50 cm3 ammonium hidroksida,NH4OH 1.0 mol dm-3

Diagram 1Rajah 1

(a)(i)

What are the types of solutions A and B.Apakah jenis larutan A dan B.

[1 mark][1 markah]

(ii)State the formula of ion that present in both solutions?Nyatakan formula ion yang hadir di dalam kedua-dua larutan?.

[1 mark][1 markah]

(iii)

Predict the pH value of Solution B, if the pH value of Solution A is 14.Ramalkan nilai pH bagi Larutan B jika nilai pH Larutan A adalah 14.

[1 mark][1 markah]

(iv)

Why there is different in pH value of Solution A and B?Mengapakah terdapat perbezaan nilai pH di antara Larutan A dan B?.

[2 marks][2 markah]

(b)Write the chemical equation between Solution A and hydrochloric acid.Tuliskan persamaan kimia antara Larutan A dengan asid hidroklorik.

[2 marks][2 markah]

(c)Calculate the volume of 0.1 mol dm-3 hydrochloric acid, HCl solution needed to neutralise Solution A.Hitungkan isipadu larutan asid hidroklorik 0.1 mol dm-3 yang diperlukan untuk meneutralkan Larutan A.

[3 marks][3 markah]

3Table 3 shows the pH values of four solutions which have the same concentration.

Jadual 3 menunjukkan nilai-nilai pH bagi empat larutan yang mempunyai kepekatan yang sama.AcidpH value

0.1 mol dm-3 hydrochloric acid0.1 mol dm-3 asid hidroklorik

1

0.1 mol dm-3 nitric acid0.1 mol dm-3 asid nitric

1

0.1 mol dm-3 ethanoic acid0.1 mol dm-3 asid etanoik

3

0.1 mol dm-3 ethanoic acid in methylbenzene0.1 mol dm-3 asid etanoik dalam metilbenzena

7

Table 3Jadual 3

(a) (i)What is meant by acid? Apakah yang dimaksudkan dengan asid?

[1 mark][1 markah

(ii)Without using any indicator, describe a chemical test to show that a solution is an acid.Tanpa menggunakan penunjuk, huraikan satu ujian kimia untuk menunjukkan bahawa suatu larutan itu berasid.

[2 marks][2 markah]

(iii)Which of the acids in Table 3 is a strong acid?Asid yang manakah dalam Jadual 3 merupakan asid kuat?

[1 mark][1 markah]

(iv) Explain why the pH value of ethanoic acid in methylbenzene is pH 7.Terangkan mengapa asid etanoik dalam metilbenzena mempunyai nilai pH 7.

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

(b) Diagram 3 shows the apparatus set-up for the titration of sodium hydroxide solution and nitric acid in an experiment.Rajah 3 menunjukkan susunan radas bagi pentitratan larutan natrium hidroksida dengan asid nitrik dalam satu eksperimen.

0.1 mol dm-3 nitric acid 0.1 mol dm-3 asid nitrik25 cm3 sodium hydroxide solution+ three drops of phenolphthalein25 cm3 larutan natrium hidroksida + tiga titis fenolftalein

Diagram 3Rajah 3

(i)Name the type of reaction that occurs in this experiment.

Namakan jenis tindak balas yang berlaku dalam eksperimen ini.

[1 mark][1 markah]

(ii)State the colour change of the solution in the conical flask when the end-point is reached.

3 (b)(ii)Nyatakan perubahan warna larutan dalam kelalang kon semasa takat akhir tercapai.

[1 mark][1 markah]

(iii)Write a balanced chemical equation for the reaction between nitric acid and sodium hydroxide solution.Tulis persamaan kimia seimbang bagi tindak balas di antara asid nitrik dan larutan natrium hidroksida.

[1 mark][1 markah]

(iv)In this experiment, 20 cm3 of nitric acid is needed to neutralize 25 cm3 of sodium hydroxide solution. Calculate the concentration of sodium hydroxide solution used.Dalam eksperimen ini, 20 cm3 asid nitrik diperlukan untuk meneutralkan 25 cm3 larutan natrium hidroksida. Hitung kepekatan larutan natrium hidroksida yang digunakan.

[2 marks][2 markah]

3.Table 3 shows the pH values of hydrochloric acid with different concentration. Jadual 3 menunjukkan nilai pH bagi asid hidroklorik dengan kepekatan yang berlainan

Concentration (mol dm3 ) Kepekatan ( mol dm3 ) pH valueNilai pH

0.11

0.012

0.0013

Table 3 [Jadual 3]

(a)Hydrochloric acid is a strong acid. What is meant by strong acid?Asid hidroklorik adalah asid kuat. Apakah yang dimaksudkan dengan asid kuat?

......[1 mark]

(b)Predict the concentration of hydrochloric acid which has a pH value of 4.Ramalkan kepekatan asid hidroklorik dengan nilai pH 4.

.....[1 mark] (c)Calculate the volume of 0.01 moldm3 hydrochloric acid that is required to prepare 1000 cm3 of hydrochloric acid with a pH value of 3.Hitungkan isipadu asid hidroklorik 0.1 mol dm-3 yang diperlukan untuk menyediakan 1000 cm3 asid hidroklorik dengan pH 3.

[2 marks](d)The pH value of 0.1 mol dm3 of ethanoic acid is 4 while the pH value of 0.1 mol dm 3 of hydrochloric acid is 1. Explain why.Nilai pH bagi 0.1 mol dm -3 asid etanoik ialah 4 manakala nilai pH bagi 0.1 mol dm -3 asid hidroklorik ialah 1. Terangkan mengapa.

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

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

...........................................................................................................................................[2 marks]

4Diagram 4.1 shows the apparatus set-up for the neutralisation reaction between nitric acid and potassium hydroxide solution for preparation of salt X.Rajah 4.1 menunjukkan susunan radas untuk tindak balas peneutralan antara asid nitrik dan larutan kalium hidroksida untuk penyediaan garam X.

20.0 cm3 of 0.5 mol dm-3 nitric acid20.0 cm3 asid nitrik 0.5 mol dm-3

20.0 cm3 of 0.5 mol dm-3 potassium hydroxide solution + phenolphthalein indicator20.0 cm3 larutan kalium hidroksida 0.5 mol dm-3 + penunjuk fenolftaleinDiagram 4.1Rajah 4.1

(a)State the colour change of the solution in the conical flask at the end point.Nyatakan perubahan warna larutan dalam kelalang kon pada takat akhir.

.

.

[1 mark]

(b)(i)State the name of salt X.Namakan garam X.

.

[1 mark]

(ii)Write a chemical equation for the above reaction.Tuliskan persamaan kimia bagi tindak balas di atas.

.

[1 mark]

(iii)Calculate the maximum mass of the salt X formed.[Molar mass of salt X = 101 g mol-1]Hitungkan jisim maksimum garam X yang terbentuk. [Jisim molar garam X = 101 g mol-1]

[3 marks]

(c)(i)The experiment is repeated with 0.5 mol dm-3 sulphuric acid to replace nitric acid. Predict the volume of sulphuric acid needed to neutralize completely.Eksperimen itu diulangi dengan menggunakan 0.5 mol dm-3 asid sulfurik bagi menggantikan asid nitrik. Ramalkan isipadu asid sulfurik yang diperlukan untuk peneutralan lengkap.

.

[1 mark]

(ii)Explain your answer in (c) (i).Terangkan jawapan anda dalam (c) (i).

.

.

.

[2 marks]

(iii)Write the ionic equation for the reaction in (c) (i).Tuliskan persamaan ion bagi tindak balas dalam (c) (i).

.

[1 mark]

7(a)The following information is about two solution of ethanoic acid. Maklumat berikut adalah tentang dua larutan asid etanoik.

Solution A:Ethanoic acid dissolve in water.Larutan A : Asid etanoik dilarutkan dalam airSolution B :Ethanoic acid dissolve in propanoneLarutan B : Asid etanoik dilarutkan dalam propanon

Explain why dry blue litmus paper turns red in solution A and remain blue in solution B. Terangkan mengapa kertas litmus biru bertukar merah dalam larutan A dan kekal biru dalam larutan B.

[4 marks]

(b)In a titration, 22.00 cm3 of 0.1 mol dm-3 sulphuric acid is required to neutralise25.00 cm3 of sodium hydroxide. Dalam satu pentitratan 22.00 cm3 asid sulfuric 0.1 mol dm-3 diperlukan untuk menuetralkan 25 cm3 larutan natrium hidroksida.

(i) Write the chemical equation of the reaction.Tulis persamaan kimia bagi tindak balas ini.

(ii) Calculate the concentration of sodium hydroxide used in this experiment. Hitung kepekatan larutan natrium hidroksida yang digunakan dalam eksperimen ini.

[6 marks]

(c)Describe the chemical tests that can be used to verify the cation and anion in magnesium nitrate. Huraikan ujian-ujian kimia yang boleh digunakan untuk mengenal kation dan anion dalam magnesium nitrat.

[10 marks]

8

(a)Table 8.1 shows information about of two acid.Jadual 8.1 menunjukkan maklumat bagi dua asid.

NameNamaConcentration/mol dm-3Kepekatan / mol dm-3pH valuenilai pH

Ethanoic acidAsid ethanoik0.53.8

Sulphuric acidAsid sulfurik0.51.0

Table 8.1

(i)What is meant by acid ?Apakah yang dimaksudkan dengan asid ?[2 marks]

(ii)Explain why these two acid have different pH values.Terangkan mengapa kedua-dua asid ini mempunyai nilai pH yang berbeza.

[4 marks]

(b)

A student carried out an experiment to investigate the chemical changes that occur to barium chloride as a result of reaction P. The result of the experiment is shown in Diagram 8.2Seorang pelajar menjalankan satu eksperimen untuk menyiasat perubahan kimia yang berlaku kepada barium klorida hasil daripada tindak balas P. Keputusan eksperimen ditunjukkan dalam Rajah 8.2

Diagram 8.2Barium chloride solution / Larutan barium kloridaSodium sulphate solution / Larutan natrium sulfatSodium chloride solution / Larutan natrium kloridaBarium sulphate precipitate / Mendakan barium sulfatReaction PTindak balas P

The chemical equation for reaction P is as follows :Persamaan kimia untuk tindak balas P adalah seperti berikut :

BaCl2 + Na2SO4 BaSO4 + 2NaCl

Excess sodium sulphate is added to 50 cm3 of 0.5 mol dm-3 barium chloride.[ Given the molar mass of BaSO4 = 233 g mol-1]Natrium sulfat berlebihan ditambahkan kepada 50 cm3 barium klorida 0.5 mol dm-3 [ Diberi jisim molar BaSO4 = 233 g mol-1]

Calculate the mass of barium sulphate formed.Hitung jisim barium sulfat terbentuk.[4 marks]

Describe the experiment how to prepare the dry barium sulphate in the laboratory.Huraikan satu eksperimen bagaimana menyediakan barium sulfat kering di dalam makmal.[7 marks]

(c)

Acid rain increases the acidity of the soil. Most plants cannot grow well in acidic soil. Hujan asid meningkatkan keasidan tanah. Kebanyakkan tumbuhan tidak dapat tumbuh dengan sempurna dalam tanah berasid.

Suggest one chemical that can be used to overcome this situation. Explain your answer.Cadangkan satu bahan kimia yang boleh digunakan untuk mengatasi keadaan ini. Terangkan jawapan anda.

[3 marks]

7(a)Table 5 shows the pH values of two alkalis solution.

AlkaliConcentration/mol dm-3pH Value

Ammonia solution0.1 11

Sodium hydroxide solution0.1 13

TABLE 5

Explain why these two solutions have different pH values. [4 marks]

(b)You are given lead (II) nitrate solution and aluminium nitrate solution. Describe chemical tests that can be used to verify the cations and anion in each solutions. [6 marks]

(c)Solid copper (II) oxide is added little by little to 25 cm3 of 1.0 mol dm-3 sulphuric acid to form copper (II) sulphate until it excess. The mixture solution is stirred. The solution is filtered. After that the filtrate is heated until it saturate. Finally it is cooled at room temperature. Copper (II) sulphate crystals is formed. [Relative atomic mass, Cu=64, S=32, O=16]

(i)Write the chemical equation for the reaction

(ii)Calculate the mass of copper (II) sulphate [4 marks]

Acid rain increases the acidity of the soil. Most plants cannot grow well in acidic soil(d)

Suggest one chemical that can be used to overcome this situation. Explain your answer. [2 marks]

9.(a)Diagram 3 shows the set-up of apparatus to prepare two solutions of hydrogen chloride in solvent X and solvent Y.Rajah 3 menunjukkan susunan radas untuk menyediakan dua larutan hydrogen klorida didalam pelarut X dan pelarut Y.

Hydrogen chlorideHidrogen kloridaBeaker ABikar ASolvent XPelarut XHydrogen chlorideHidrogen kloridaBeaker BBikar BSolvent YPelarut Y

Diagram 3 [ Gambarajah 3]

Table 5 shows the pH values of two solutions of hydrogen chloride in solvent X and solvent Y SolutionLarutanpH ValueNilai pH

Hydrogen chloride in solvent XHidrogen klorida dalam pelarut X7

Hydrogen chloride in solvent YHidrogen klorida dalam pelarut Y1

Table 5 [Jadual 5]

(i) Name possible substances that can be solvent X and solvent YNamakan bahan yang mungkin adalah pelarut X dan pelarut Y[ 2 marks]

(ii) Describe an experiment to differentiate the two solutions of hydrogen chloride in solvent X and solvent YHuraikan satu ujian kimia untuk membezakan dua larutan hidrogen klorida di dalam pelarut X dan pelarut Y [ 6 marks]

(b)(i) Which of the two hydrogen chloride solution in Table 5 can be used to prepare a soluble zinc salt? Explain your answer.Antara larutan hidrogen klorida yang mana dalam Jadual 5 boleh digunakan untuk menyediakan satu garam zink terlarut. Terangkan jawapan anda.[2 marks]

(ii)Hydrogen chloride dissolve in water to form hydrochloric acid. Starting from hydrochloric acid and a suitable compound, describe an experiment to prepare a sample of dried zinc chloride crystals.Hidrogen klorida larut dalam air membentuk asid hidroklorik. Bermula dari asid hidroklorik, huraikan satu eksperimen untuk menyediakan hablur garam terlarut zink klorida yang kering. [ 10 marks]

7(a)The following information is about two solution of ammonia.Maklumat berikut adalah tentang dua larutan ammonia.

Solution A: Ammonia dissolve in water.Larutan A : Ammonia dilarutkan dalam air.Solution B: Ammonia dissolve in methylbenzeneLarutan B : Ammonia dilarutkan dalam metilbenzena.

Explain why dry red litmus paper turns blue in solution A and remain red in solution B.Terangkan mengapa kertas litmus merah bertukar biru dalam larutan A dan kekal tidak berubah dalam larutan B.

[4 marks]

(b)In a tiration, 22.00 cm3 of 0.1 mol dm-3 hydrochloric acid is required to neutralise 25.00 cm3 of potassium hydroxide solution.Dalam satu pentitratan 22.00 cm3 asid hidroklorik diperlukan untuk meneutralkan 25.00 cm3 larutan kalium hidroksida.

(i)Write the chemical equation of the reaction.Tulis persamaan kimia bagi tindak balas ini.

(ii)Calculate the concentration of potassium hydroxide used in this experiment.Hitung kepekatan larutan kalium hidroksida yang digunakan dalam eksperimen ini.

[4 marks]

(c)The sting of a jelly-fish is alkaline and caused pain.Suggest one substance that can applied to the skin to relieve the pain without causing further injury. Explain your answer.Sengatan obor-obor adalah beralkali dan menyebabkan kesakitan.Cadangkan satu bahan yang boleh disapu pada kulit untuk mengurangkan sakit tanpa menyebabkan kecederaan seterusnya.Terangkan jawapan anda.

[2 marks]

(d)Table 7 shows the information and pH value of sulphuric acid and ethanoic acid.Jadual 7 menunjukkan maklumat dan nilai pH bagi asid nitrik dan asid etanoik.

AcidAsidpH

1.0 mol dm-3 nitric acidAsid nitric 1.0 mol dm-31

1.0 mol dm-3 ethanoic acidAsid etanoik 1.0 mol dm-35

Table 7Jadual 7

Based on information in Table 7, compare between nitric acid and ethanoic acid. Your comparison should refer to the following aspects: chemical formula, basicity, the ions formed when ionised in water, ionisation equation, degree of ionisation and the strength of both acids. Berdasarkan maklumat dalam Jadual 7, bandingkan antara asid nitrik dan asid etanoik. Perbandingan anda hendaklah merujuk kepada aspek-aspek berikut: Formula kimia, kebesan, ion-ion yang terbentuk apabila mengion dalam air, persamaan pengionan, darjah pengionan dan kekuatan untuk kedua-dua asid.

[10 marks]

Acid shows its acidic properties only in the presence of water but cannot show its acidic properties in organic solvent.Asid hanya menunjukkan sifat-sifat asid apabila larut dalam air tetapi tidak menunjukkan sifat-sifat asid apabila larut dalam pelarut organik.2

Based on the statement above, plan a laboratory experiment to investigate the role of water in showing the properties of acid.Berdasarkan pernyataan di atas, rancang satu eksperimen makmal untuk mengkaji peranan air untuk menunjukkan sifat asid.

Your planning should include the following aspects:Perancangan anda hendaklah mengandungi aspek berikut:1. Problem statement Pernyataan masalah

1. All the variables Semua pemboleh ubah

1. Hypothesis Hipotesis

1. List of materials and apparatus Senarai bahan dan radas

1. Procedure Prosedur

1. Tabulation of data Penjadualan data

[17 marks]