module 4 the rate of reaction

7/30/2019 Module 4 the Rate of Reaction

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MODUL PECUTAN AKADEMIK KIMIA 4541

2012HAK CIPTA JABATAN PELAJARAN KELANTAN

1 [Lihat halaman sebelah]

Nama Pelajar: Tingkatan:..

JABATAN PELAJARAN KELANTAN

MODUL PECUTAN AKADEMIK TAHUN 2012

SIJIL PELAJARAN MALAYSIA

KIMIA

4541

JANGAN BUKA MODUL INI SEHINGGA DIBERITAHU

1. Modul ini mengandungi 7 soalan.

2. Jawab semua soalan.

3. Anda dibenarkan menggunakan kalkulator saintifik.

Modul ini mengandungi 17 halaman bercetak.


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MODULE 4 :RATE OF REACTION

Bahagian AStruktur

1 A group of students carried out two experiments to investigate one factor that affects the rate of

a reaction .

Sekumpulan pelajar menjalankan dua eksperimen untuk mengkaji satu faktor yang

mempengaruhi kadar suatu tindak balas.

Experiment 1: Excess granulated of metal zinc is added to 25 cm3

of 0.2 mol dm-3

hydrochloric acid.

Eksperimen 1: Ketulan logam zink berlebihan di tambah kepada 25 cm3

asid hidroklorik

0.2 mol dm-3

Experiment 2: Excess powder of metal zinc is added to 25 cm3

of 0.2 mol dm-3

hydrochloric acid.

Eksperimen 2: Serbuk logam zink berlebihan di tambah kepada 25 cm3

asid hidroklorik

0.2 mol dm-3

(a) (ii) Write the chemical equation for this reaction.

Tuliskan persamaan kimia bagi tindak balas ini.

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

(iii) Calculate the maximum volume of hydrogen gas released at room condition.

[Molar volume of gas at room condition: 24 dm3mol

-1]

Hitungkan isi padu maksima gas hidrogen yang terbebas pada keadaan bilik.

[Isi padu molar gas pada keadaan bilik: 24 dm3

mol-1

]

[3 marks]


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(b) Diagram 5 shows the results of experiment 1.

Rajah 5 menunjukkan keputusan eksperimen 1.

Diagram 5

Rajah 5

(i) Sketch the curve for experiment 2 on diagram 5.

Lakarkan lengkung bagi eksperimen 2 pada rajah 5.

[2 marks]

(ii) What is the factor that affects the rate of reaction in this experiment.

Apakah faktor yang mempengaruhi kadar tindak balas dalam eksperimen ini.

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

[1 mark]

(iii) Compare the rate of reaction between experiment 1 and experiment 2.

Give a reason.Bandingkan kadar tindak balas antara eksperimen 1 dan eksperimen 2.Berikan satu sebab.

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

..................................................................................................................................... [3 marks]

Volume of hydrogen gas

Isi padu gas hidrogen

(cm3

)

Time (s)

Masa (s)


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2 Two experiments are carried out to investigate the rate of reactionof magnesium reacts with

sulphuric acid.Table 2 shows the resultsof Experiment I and II.

Dua eksperimen telah dijalankan untuk mengkaji kadar tindak balas bagi tindak balas

antara magnesium dan asid sulfurik.Jadual 2 menunjukkan keputusan EksperimenI dan II.

Experiment

Eksperimen

Reactant

Bahan tindak balas

Temperature/oC

Suhu/0C

Total volume of gas

collected in

2 minutes /cm3

Jumlah isi padu gas

yang dikumpulkan

dalam2 minit /cm3

I

Excess magnesiumpowder + 20 cm3 of 0.1

mol dm

-3

sulphuric acid

Serbuk magnesium

berlebihan + 20 cm30.1

mol dm-3

asid sulfurik

30 22.0

II

Excess magnesiumpowder + 20 cm3 of 0.1

mol dm-3 sulphuric acid

Serbuk magnesium

berlebihan + 20 cm

3

0.1 mol dm-3

asid sulfurik

40 37.0

Table 2

Jadual 2

(a) Write the ionic equation for the reaction betweenmagnesium and sulphuric acid.

Tuliskan persamaan ion bagi tindak balas magnesium dan asid sulfurik.

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


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(b) Calculate the average rate of the reaction for the first two minutes in cm3 s-1.

Hitungkan kadar tindak balas purata bagi dua minit pertama dalam cm3

s-1

.

(i) Experiment I :Eksperimen I :

(ii) Experiment II :

Eksperimen II :

[ 2 marks]

(c) Calculate the maximum volume of gas produced in Experiment II.

[1 mol of gas occupies 24 dm3 at room condition]

Hitungkan isipadu maksimum gas yang dibebaskan dalam Eksperimen II.[1 mol gas menempati 24 dm3pada keadaan bilik]

[2marks]


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(d) Sketch the graphs of the total volume of gas collected against time for Experiment IAnd Experiment II on the same axes.

Pada paksi yang sama, lakarkan graf isipadu gas yang terkumpul melawan masa

untuk Eksperimen I dan Eksperimen II.

[2 marks]

(e) Compare the rate of reaction betweenExperiment I and Experiment II.Explain why there is a difference in the rate of reaction based on the collision theory.

Bandingkan kadar tindak balas antara Eksperimen I dan Eksperimen II.

Terangkan kenapa terdapat perbezaan kadar tindak balas itu berdasarkan teori

perlanggaran.

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

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

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

[3 marks]


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3 An experiment is carried out to determine the rate of reaction between excess calcium

carbonate and 50.0 cm3

of 0.2 mol dm-3

hydrochloric acid. The volume of carbon dioxide gasproduced is recorded at 30 seconds intervals. The result obtained is recorded in Table 3.

Satu eksperimen telah dijalankan untuk menentukan kadar tindak balas antara

50.0 cm3

asid hidroklorik 0.2 mol dm-3

dengan kalsium karbonat berlebihan. Isipadi gas

karbon dioksida yang terbebas direkodkan pada setiap 30 saat dalam Jadual 3.

Time/s 0 30 60 90 120 150 180 210 240

Volume/cm 0 17 29 34 36 36 36 36 36

Table 3

Jadual 3

(a)

(b)

Based on Table 3, draw a graph of volume of carbon dioxide gas against time.

Berdasarkan Jadual 3, lukis graf isipadu gas karbon dioksida melawan masa.

[4 marks]

Calculate the average rate of reaction for this experiment.Hitungkan kadar tindak balas purata bagi tindak balas ini.

[2 marks]

(c) If the experiment is repeated by using 50.0 cm3 of 0.1 mol dm-3 hydrochloric acid,sketch the expected curve in graph (a) .

Jika eksperimen diulangi menggunakan 50.0 cm3 asid hidroklorik 0.1 moldm-3, lakarkan

lengkung yang dijangkakan dalam graf (b).

[2 marks]

(d) The factor that affects the rate of reaction in this experiment is concentration. State two

other factors that can affect the rate of reaction in this experiment.

Faktor yang mempengaruhi kadar tindak balas dalam eksperimen ini ialah kepekatan.

Nyatakan dua lagi faktor yang dapat mempengaruhi kadar tindak balas eksperimen ini.

.

.

[2 marks]


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Essei

4 (a)

(i)

(ii)

The statement below shoes that one of the factor that affect the rate of reaction is

the size of the reactant.

Pernyataan di bawah menunjukkan bahawa salah satu faktor yang mempengaruhikadar tindak balas ialah saiz bahan.

State two other factors that affect rate of reaction.

Nyatakan dua faktor lain yang mempengaruhi kadar tindak balas.

[ 2 marks]

Explain the effect of one factor stated in 1(a)(i) on rate of reaction based on thecollision theory.

Terangkan kesan salah satu faktor yang dinyatakan dalam 1(a)(i) ke atas kadar

tindak balas berdasarkan teori perlanggaran.

[ 4 marks]

(b)

24 cm3

of carbon dioxide gas was collected in a reaction between calciumcarbonate and hydrochloric acid after 100 seconds as shown in the above equation.Calculate the average rate of reaction.

24 cm3 gas karbon dioksida dibebaskan dalam tindak balas antara kasiumkarbonat dan asid hidroklorik selepas 100 saat seperti yang ditunjukkan di dalam

persamaan di atas. Kira kadar purata tindak balas ini.

[ 2 marks]

Mimi bought 1 kg of meat. She realizes that meat which is cut into bigpieces will take a longer time to cook. The same meat if cut into small

pieces will take a shorter time to cook under the same cooking conditions.

Mimi membeli 1kg daging. Dia menyedari bahawa daging yang dipotongbesar mengambil masa yang lama untuk masak. Daging yang sama jika

dipotong kecil mengambil masa yang singkat untuk masak dalam keadaan

yang sama.

CaCO3(s) + 2HCl(aq) CaCl2(aq) + CO2(g) + H2O (l)


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(c)

A student intends to investigate the effect of concentration on the rate of reaction

between sodium thiosulphate solution and sulphuric acid.Describe one laboratory experiment to study the effect of concentration on the rate

of reaction.

Your answer should include the following:

List of materials and apparatus Procedure of the experiment

Sketch a graph to show the relationship between the rate of reaction andconcentration

Seorang pelajar ingin menyiasat kesan kepekatan ke atas kadar tindak balas

antara larutan natrium thiosulfat dan asid sulfurik.

Huraikan satu eksperimen untuk mengkaji kesan kepekatan ke atas kadar tindak

balas.

Jawapan anda perlu mengandungi perkara berikut:

Senarai bahan dan radas

Prosedur eksperimen Lakarkan graf untuk menunjukkan hubungan antara kadar tindak balas

dengan kepekatan.

[12 marks]


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5 Table 5 shows the data from Experiment I and Experiment II that were carried out to study the

rate of reaction of zinc with two acids, hydrochloric acid and acid P.Jadual 5 menunjukkan data daripada Eksperimen I dan Eksperimen II yang dijalankan untuk

mengkaji kadar tindak balas antara zink dengan dua asid, asid hidroklorik dan asid P.

Experiment

Eksperimen

Reactants

Bahan tindak balas

Product

Hasil tindak

balas

Observation

Pemerhatian

I

2.6 g of zinc and 50 cm ofhydrochloric acid, HCl 2.0 mol

dm-3

2.6 g zink dengan 50 cm3 asid

hidroklorik,HCl

2.0 mol dm-3

Zinc chlorideand hydrogen

gas

Zink klorida

dan gas

hidrogen

The temperature of

the mixtureincreases

Suhu campuran

meningkat

II

2.6 g of zinc and 50 cm3

of

acid P 2.0 mol dm-3

2.6 g zink dengan 50 cm3

asid

P 2.0 mol dm-3

Zink ethanoateand hydrogen

gas

Zink ethanoate

dan gas

hidrogen

The temperature ofthe mixture

increases

Suhu campuran

meningkat

Table 5

Jadual 5

(a) (i) State the name of acid P.

Write a balanced chemical equation for the reaction of this acid with zinc.Namakan asid P.

Tuliskan persamaan kimia yang seimbang bagi tindak balas asid ini dengan zink.

[3 marks]

(ii) Catalyst is needed to increase the rate of reaction in Experiment I.

Draw an energy profile diagram for Experiment I.On the energy profile diagram, show the

Activation energy without catalyst, Ea

Activation energy with catalyst, Ea

Explain the energy profile diagram.Lukis satu gambar rajah profil tenaga untuk tindak balas dalam Eksperimen I.

Pada gambar rajah profil tenaga itu tunjukkan:

Tenaga pengaktifan tanpa mangkin,Ea.

Tenaga pengaktifan dengan mangkin, EaTerangkan gambar rajah profil tenaga itu.

[7 marks]


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(b) Another experiment is carried out to study the factors that affect the rate of the reaction.

Diagram 5 shows a graph obtained from an experiment using magnesium ribbon thatreacts with dilute hydrochloric acid.

Eksperimen lain telah dijalankan untuk mengkaji faktor yang mempengaruhi kadar

tindak balas.

Rajah 5 menunjukkan graf yang diperolehi daripada eksperimen menggunakan pitamagnesium yang bertindak balas dengan asid hidroklorik cair.

I

Time/sMasa/s

Diagram 5

Rajah 5

(i) If curve I represents the result from the experiment using excess magnesiumribbon reactingwith 50 cm3 of 0.5 mol dm-3hydrochloric acid,

describe briefly an experiment to obtain the curve labelled II.

Jika lengkung I mewakili keputusan eksperimen menggunakan pita magnesium

berlebihan yang bertindak balas dengan 50 cm3

0.5 mol dm-3

asid hidroklorik,

huraikan dengan ringkas suatu eksperimen untuk mendapatkan lengkung berlabel

II.

[3 marks]

Volume of hydrogen gas/cm

Isipadu gas hydrogen/cm3

III

II

2V

VI


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(ii) State the reason for your suggested changes in (b)(i) and explain based on the

collision theory.Nyatakan sebab bagi cadangan perubahan dalam (b)(i) dan terangkan

berdasarkan Teori Perlanggaran.

[ 6 marks]

(iii) Suggest one factor that influence the rate of reaction to obtain curve III.

Cadangkan satu faktor yang mempengaruhi kadar tindak balas untuk

mendapatkan lengkung III.

[ 1 mark]

Kertas 3 ( Soalan Struktur)

6 Diagram 6.1 and 6.2 shows the readings of the burette for two set of the experiment to

study the effect of the amount of catalyst on the rate of reaction.

0.2 g of manganese (IV) oxide powder is added to 30 cm of 20-volume hydrogenperoxide solution. The volume of gas released is collected and the burrette reading is

recorded at every 30 seconds intervals.

The experiment was repeated using 0.6 g of manganese (IV) oxide powder.

Rajah 6.1 dan 6.2 menunjukkan bacaan buret bagi dua set eksperimen yang

dijalankan untuk mengkaji kesan kuantiti mangkin ke atas kadar tindak balas.

0.2 g serbuk mangan (IV) oksida ditambahkan kepada 30 cm larutan 20-isipadu

hidrogen peroksida. Isipadu gas yang terbebas dikumpulkan dan bacaan buretdirekodkan pada setiap 30 saat.

Eksperimen ini diulangi menggunakan 0.6 g serbuk mangan (IV) oksida.


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Time (s)

Masa (s)

0 30 60 90 120 150 180

Experiment IEksperimen I

Burette

reading/cm3

Bacaanburet/cm

3. .

Diagram 6.1

Rajah 6.1

Time (s)

Masa (s)

0 30 60 90 120 150 180

Experiment IIEksperimen II

Burette

reading/cm3

Bacaan

buret/cm3

. . ..

Diagram 6.2

Rajah 6.2


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( a ) Record the burette reading for each of the experiment in the spaces provided.

Rekod bacaan buret bagi setiap eksperimen di ruangan yang disediakan.

[3 marks]

(b) Construct a table and record the burette reading and the volume of oxygen gas collectedfor Experiment l and Experiment ll.

Bina jadual dan rekodkan bacaan buret dan isipadu gas oksigen yang dikumpulkan bagi

Eksperimen l dan Eksperimen ll.

[3 marks]

(c) Based on the experiment, state the operational definition for rate of reaction.

Berdasarkan eksperimen, nyatakan definisi secara operasi bagi kadar tindak balas.

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

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

[3 marks]

(d) Plot a graph of volume of oxygen gas collected against time for both experiment on the

graph paper provided.

Plot graf isipadu gas oksigen yang terkumpul terhadap masa bagi kedua-dua eksperimen

di atas kertas graf yang disediakan.

[3 marks]


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(e) Based on the graph in (d), state the relationship between the amount of catalyst used and

the rate of reaction.Berdasarkan graf di (d), nyatakan hubungan antara kuantiti mangkin digunakan dengan

kadar tindak balas.

[3 marks]

(f) State all the variables for this experiment.

Nyatakan semua pembolehubah bagi eksperimen ini.

Manipulated variable:

Pemboleh ubah dimanipulasikan:

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

Responding variable:

Pemboleh ubah bergerak balas:

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

Fixed variable:

Pemboleh ubah dimalarkan

.

[3 marks]

(g) Sketch the graph obtained if both of the experiments are continued until the reaction is

complete.

Lakarkan bentuk graf yang akan diperolehi apabila kedua-dua eksperimen ini diteruskan

sehingga tindak balas lengkap.

[3 marks]

[3 markah]


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Kertas 3 ( Soalan Esei)

7 Reaction I /Tindak balas I

Reaction II /Tindak balas II

By using the information of Reaction I or Reaction II, plan an experiment to investigate the

effect of temperature on the rate of reaction. Your planning should include:

Dengan menggunakan maklumat Tindak balas Iatau Tindak balas II, rancang satu

eksperimen untuk mengkaji kesan suhu ke atas kadar tindak balas. Perancangan anda

hendaklah mengandungi:

(i) Problem statement

Pernyataan masalah

(ii) All the variables

Semua pembolehubah

(iii) HypothesisHipotesis

(iv) List of material and apparatus

Senarai bahan dan alat radas

(v) Procedure

Prosedur

(vi) Tabulation of data

Penjadualan data

[17 marks]

Reaction between sodium thiosulphate, Na2S2O3 solution and dilute sulphuric acid,

H2SO4 will produce sodium sulphate, Na2SO4, sulphur, S, sulphur dioxide, SO2

and water, H2O. The chemical equation is:

Tindak balas antara larutan natrium tiosulfat, Na2S2O3 dan asid sulfurik cair,

H2SO4 akan menghasilkan natrium sulfat, Na2SO4, sulfur, S, sulfur dioksida, SO2

dan air, H2O. Persamaan kimia adalah:

Na2S2O3 + H2SO4 Na2SO4 + S + SO2 + H2O

Reaction between hydrochloric acid, HCl and zinc, Zn will produce zinc chloride,

ZnCl2 and hydrogen gas, H2. The chemical equation is:

Tindak balas antara asid hidroklorik, HCl dan zink, Zn akan menghasilkan zink

klorida, ZnCl2 dan gas hydrogen, H2. Persamaan kimia adalah:

2HCl + Zn ZnCl2 + H2


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Marking Scheme Module Pecutan Akademik 2012

RATE OF REACTIONNo Explanation Mark

1 (a)(i) Zn + 2HCl ZnCl2 + H2 1+1

(ii) Mol = 0.2 x 25 /1000//0.005

Mol H2 = 0.005/2//0.0025Volume of H2 = 0.0025 x 24000//60cm

3

1

11

(b)(i)

Slope of the curve is steeperMaximun volume is the same 1 + 1

(ii) Size of zinc//Total surface area of the zinc 1

(iii) Rate of experiment 2 is higher than experiment 1

When the total surface area is higher The frequency of collision between

zinc atom and H

+

is increasedThe frequency of effective collision betwee particles is increased

1

1

1

Total 11

2 (a) Mg + 2H+Mg+ + H2

1 correct formulae of reactants and products2 balanced equation

11

(b) Experiment I :

Rate of reaction =602

22

= 0.183 cm3

s-1

Experiment II :

Rate of reaction =602

37

= 0.308 cm3

s-1

1

1


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(c) Maximum volume

No of mole = 20 x 0.1 /1000

= 0.002Volume of gas = 0.002 x 24

= 0.048dm3

1

1

(d) Volume of

H2/ cm3

Time/s

1. Axes are labelled correctly and have correct unit2. Correct curves and curves are labelled

11

(e) 1. The rate of reaction in experiment II is higher

2. Experiment II has higher temperature3. Frequency ofeffective collisions between hydrogen ions and

magnesium higher in experiment II.

1

11

Total 11

3 (a) Labelling of axis is correct

Suitable scaleTransferring of point is correct

Graph is smooth and start from zero

1

11

1

(b) 36

120= 0.3 cm3s-1

1

1

II

I


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(c)

The curve of graph II is less steep than the curve of graph 1.The volume of gas produced in experiment II is half produced in

experiment 1.

1

1

(d) TemperatureTotal surface area 11

Total 10

Essei

4 (a)

(i)

Two other factors that affect the rate of reaction

- Concentration of reactant- Temperature

- Pressure- Use of catalyst[ Any two correct answers ]

2

(ii) Based on collision theory explain factors:*Concentration:

- The higher the concentration of reactants, the higher the number ofparticles in a unit volume

- The frequency of collision between particles increases- The frequency of effective collision increases- The rate of reaction increases

*Temperature of the reactant- The higher the temperature, the higher the kinetic energy ofreactant particles.

- The frequency of collision between particles increases- The frequency of effective collision increases- The rate of reaction increases

*Adding catalyst

1

1

1

1

I

11

Time/s

Volume of gas/cm


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- By adding catalyst to the reactant, it provides an alternative path with a

lower activation energy.-- More particles can overcome the activation energy- The frequency of effective collision increases- The rate of reaction increases

-Pressure- The higher the pressure of the reactant, the higher the number of

particles in a unit volume- The frequency of collision between particles increases- The frequency of effective collision increases- The rate of reaction increases

[*Any one explanation ]

(b) 24 cm100 s

= 0.24 cm3

s-1

[ units is compulsory]

1

1

(c)

--material :sodium thiosulphate solution [ 0.20.5 mol dm

-3] ,

hydrochloric acid [ 1.0 to2.0 mol dm-3]

-apparatus :[50100 cm3] measuring cylinder, 10 cm

3measuring cylinder,

[100 - 250 cm3

] conical flask, stop watch, paper

Procedure:

1. Measure 50 cm3

of sodium thiosulphate solution [ using ameasuring cylinder ] and poured into a conical flask.

2. Place the conical flask on a piece of paper marked with an X.3. Measure 5 cm

3of sulphuric acid and add into the conical flask.

4.Start the stopwatch quickly.5.Stop the stop watch when the X mark becomes invisible/ not seen..

6.Record the time.7. Repeat step 1 to 6 using different concentrations of sodiumthiosulphate solution.

Chemical equations of the reactionNa2S2O3 + H2SO4 Na2SO4 + H2O + S + SO2

Correct reactants1 mark

1

1

1

1

11

11

1

1

Max

5


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5(a)(i) Ethanoic acid

2 CH3COOH + Zn ( CH3COO)2Zn + H2

Correct formula of reactant and product

Balance

1

1

1

(ii)

Reaction path

The energy difference between the maximum energy of the curve and the

energy of the reactant is activation energy

When catalyst is added, the activation energy is lowered

Correct products1 mark

Graph:

Correct axes with units1 mark

Correct straight line 1 mark

2

2

Total 20

1 s-

Time

Concentration Na2S2O3 ,mol dm-

Zn + 2HNO

Zn(NO3)2 + H2

Ea

Ea

Energy


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(b)(i) 50 cm 1.0 mol dm - HCl is measured and poured into the conical flack

Magnesium ribbon is added

The volume of gas is collected at regular interval //30 seconds intervals

1

1

1

(ii) When the concentration of HCl is double/ higherThe concentration of hydrogen ion higher

The number of H+ per unit volume increases

The frequency of collision between H+

ion and Mg atom increases

The frequency of effective collision between particles increasesRate of reaction higher/double

11

1

1

11

(iii)

Temperature//catalyst//size of magnesium 1

Total

= 20

Kertas 3 (Soalan Struktur)

Question Mark Scheme Mark

6(a) Able to record the burette reading for Experiment 1 and Experiment 2

correctly with 2 decimal point correctly.

Answer:

Burette

reading/ cm3

Bacaan

buret/ cm3

50.00 43.00 38.00 34.00 30.00 27.00 25.00

Burette

reading/ cm3

Bacaan

buret/ cm3

50.00 37.00 29.00 23.00 19.00 16.00 14.00

3


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Question Mark Scheme Score

6(b) Able to construct a table and record the burette reading and the volume ofoxygen gas collected for Experiment 1 and Experiment 2 correctly.

Sample Answer:

Experiment 1

Time(s) 0 30 60 90 120 150 180

Burette

reading/ cm3

Bacaan

buret/ cm3

50.00 43.00 38.00 34.00 30.00 27.00 25.00

Volume of

O2 gas/ cm3

Isipadu gas

O2 / cm3

0.00 7.00 12.00 16.00 20.00 23.00 25.00

Experiment 2

Time(s) 0 30 60 90 120 150 180

Burette

reading/cm3

Bacaanburet/ cm

3

50.00 37.00 29.00 23.00 19.00 16.00 14.00

Volume of

O2 gas/ cm3

Isipadu gas

O2 / cm3

0.00 13.00 21.00 27.00 31.00 34.00 36.00

3


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2(c) Able to state the operational definition for rate of reaction correctly.

Sample answer:

The change in volume of oxygen gas released per second.Perubahan isipadu gas oksigen yang terbebas setiap saat.

3

2(d) Able to plot a graph of volume of oxygen gas collected against time for

Experiment 1 and 2 with the following aspects correctly.

Answer:

1. X and Y axis with correct label and unit.2. correct and smooth graph3. suitable scale

3

2(e) Able to state the relationship between the amount of catalyst used andthe rate of reaction correctly.

Answer:

An increase in the amount of manganese (IV) oxide will increase the

rate of reaction.

Apabila kuantiti mangan (IV) oksida bertambah kadar tindak balasakan meningkat.

3

2(f) Able to state all the variables for this experiment correctly.

Answer:

Manipulated variable:Mass of catalyst

Jisim mangkin

Responding variable:Rate of reaction

Kadar tindak balas

Fixed variable:

Concentration of hydrogen peroxide solution.

Kepekatan larutan hidrogen peroksida

3


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2(g) Able to sketch the graph obtained correctly if both of the

experiments are continued until the reaction is complete.

Answer:

3

Kertas 3(esei)

Question

No.

Rubric Score

2 (i) Able to give the statement of the problem accurately. Response is in

question form.

Sample answer:

Does the temperature of sodium thiosulphate solution affect the rate of

reaction? //

How does the temperature of sodium thiosulphate solution affect the rate

of reaction? //

How does the high / low temperature of sodium thiosulphate solutionaffect the rate of reaction?

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Question

No.Rubric Score

2 (ii) Able to state the three variables correctly

Sample answer:


Temperature of sodium thiosulphate solution

Rate of reaction // Time taken for mark X to become invisible/disappear

Constant variable:

Volume and concentration of sodium thiosulphate/ sulphuric acid /

size of conical flask

3

2 (iii) Able to state the relationship correctly between the manipulatedvariable and the responding variable with direction.

Sample answer:

The higher/lower the temperature of sodium thiosulphate solution,

the higher/lower the rate of reaction. //

The higher/lower the temperature of sodium thiosulphate solution,

the shorter/longer the time taken for markX to disappear fromsight/view //

The increase/decrease in temperature of sodium thiosulphate solutionwill increase/decrease the rate of reaction. //

When the temperature of sodium thiosulphate solution increase

/decrease, the rate of reaction will increase/decrease.

3

2 (iv) Able to give complete list of materials and apparatus

Sample answer:

Materials:

Sodium thiosulphate solution, sulphuric acid.

Apparatus:

Conical flask, ,bunsen burner, measuring cylinder (10 ml), measuring

cylinder (50 ml), stop-watch, filter /white /cardboard paper.

3


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Question

No.Rubric Score

2 (v) Able to list all the steps correctly

Sample Answer:

1. X mark is drawn on a piece of white/filter/ cardboard paper.2. 50 cm3 of sodium thiosuphate solution [(0.01-1.0) mol dm-3]

is measured with a (50 cm3 ) measuring cylinder and is

poured into a conical flask.

3. The solution is slowly heated until 30 oC.4. 5 cm3 of hydrochloric acid [(0.1- 2.0) mol dm-3] is measured

with a (10 cm3)measuring cylinder and is added to the conical

flask. A stop-watch is started immediately.5. The conical flask is swirled and is placed on a

white/filter/cardboard paper with a markX.6. The X mark is observed vertically from the topthrough the solution.

7. The stop-watch is stopped immediately when the X markcannot be seen. Time is recorded.

8. The experiment is repeated by using the sodium thiosuphatesolution at 40 oC, 50 oC, 60 oC and 70 oC respectively.

3

2 (vi) Able to tabulate the data with following aspects

1. Correct titles with units

2. Complete list of temperatures

Sample answer:

Temperature (oC)Time

(s)

30

40

50

60

70

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Able to contruct a table.

1. At least 1 titles correct without units

2. Incomplete list of tempereatures

Sample answer:

Temperature

30

1

Experiment 2: 2HCl + Zn ZnCl2 + H2

Question

No. Rubric Score

2 (i) Able to give the statement of the problem accurately. Response is inquestion form.

Sample answer:

Does the temperature of hydrochloric acid solution affect the rate of

reaction? //

How does the temperature of hydrochloric acid solution affect the rate

of reaction? //

How does the high / low temperature of solution affect the rate

hydrochloric acid of reaction?

3

2 (ii) Able to state the three variables correctly

Sample answer:


Temperature of hydrochloric acid

Responding variable:

Rate of reaction // Volume of gas per unit time

Constant variable:

Mass/size of zinc //Volume and concentration of hydrochloric acid

3


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Question

No.Rubric Score

2 (iii) Able to state the relationship correctly between the manipulated

variable and the responding variable with direction.

Sample answer:The higher/lower the temperature of hydrochloric acid, the

higher/lower the rate of reaction. //

The higher/lower the temperature of hydrochloric acid, the

higher/lower the volume of the hydrogen gas release per unit time //

The increase/decrease in temperature of hydrochloric acid will

increase/decrease the rate of reaction. //

When the temperature of hydrochloric acid increases/decreases, the rate

of reaction will increase/decrease.

3

2 (iv) Able to give complete list of materials and apparatus

Sample answer:

Materials:Zinc, hydrochloric acid

Apparatus:

Conical flask, thermometer , bunsen burner, stop-watch

measuring cylinder (50 ml), delivery tube and stopper, burette, basin,

3

2 (v) Able to list all the steps correctly

Sample Answer:1. Burette is filled with water and inverted into a basin containing

water.

2. The burette is clamped vertically using retort stand.3. Initial reading of burette is recorded.

4. [20-50] cm3

of hydrochloric acid [(0.01-1.0) mol

dm-3

] is measured with a (50 ml) measuring cylinder

and is poured into a conical flask.5. The solution is slowly heated until 30 oC.

6. 2 g of zinc is weighed, and is put into the conical

flask.7. The conical flask is closed immediately with a

stopper which is joined to the delivery tube and

the stopwatch is started.8. The burette reading is recorded at interval of 30

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seconds until the reaction is completed.

9. The experiment is repeated by using thehydrochloric acid at 40

oC, 50

oC, 60

oC and

70 oC respectively.

2 (vi) Able to tabulate the data with following aspects

1. Correct titles with units

2. Complete list of temperatures

Sample answer:

Temperature (oC)Time

(s)

30

40

50

60

70

2

END OF MARKING SCHEME

module 4 the rate of reaction

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