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SULIT4551/31 A group of students conducted an experiment to study the level of water pollution from four different sources. Areas P, Q, R and S were chosen.Sekumpulan pelajar menjalankan satu eksperimen untuk mengkaji tahap pencemaran air dari empat sumber yang berbeza. Kawasan P, Q, R dan S telah dipilih.

The students carried out the following steps:Pelajar-pelajar tersebut menjalankan langkah-langkah berikut:Step 1:1 ml of 0.1 % methylene blue solution was added to water sample P in a reagent bottle.Langkah 1 :1 ml larutan 0.1% metilena biru ditambah kepada sampel air P dalam botol reagen.Step 2 :The reagent bottle was kept in a dark cupboard.Langkah 2 :Botol reagen tersebut disimpan dalam sebuah almari yang gelap. Step 3:The bottle is examined and the time taken for the decolourisation of methylene blue in the water sample is recorded.Langkah 3 :Botol tersebut diperiksa dan masa untuk penyahwarnaan metilena biru bagi sampel air tersebut direkodkan.

Diagram 1 shows the method used in the experiment.Rajah 1 menunjukkan kaedah yang digunakan dalam eksperimen ini.

Diagram 1 Rajah 1

Steps 1 to 3 are repeated for water samples Q, R and S. The time taken for decolourisation of methylene blue solution is shown in Diagram 2.Langkah 1 hingga 3 diulangi untuk sampel air Q, R, dan S. Masa yang diambil untuk pelunturan larutan metilena biru ditunjukkan dalam Rajah 2.

Water sample, PSampel air, PWater sample, QSampel air, Q

minute minit

minit

minuteminit

Water sample, RSampel air, RWater sample, SSampel air, S

minuteminit

minute minit

Diagram 2 Rajah 2

(a)(i)Based on Diagram 2, state two observations on the relationship between water sample and time taken for decolourisation of methylene blue solution.Berdasarkan Rajah 2, nyatakan dua pemerhatian mengenai hubungan antara sampel air dan masa penyahwarnaan larutan metilena biru.

1. ________________________________________________________________________________________________________________________31 (a) (i)

2. ____________________________________________________________ ____________________________________________________________

(ii)State the inferences which correspond to the observations in l(a)(i).Nyatakan inferens yang sepadan dengan pemerhatian di 1(a)(i).

Inference 1 : ______________________________________________________Inferens 1 ______________________________________________________

Inference 2 : ______________________________________________________31 (a) (ii)

Inferens 2 _________________________________________________________

31 (b)

(b)Record the time taken for decolourisation of methylene blue solution for the water samples in the spaces provided in Diagram 2.Rekodkan masa yang diambil untuk penyahwarnaan larutan metilena biru dalam sampel-sampel air dalam ruang yang disediakan di Rajah 2.(c)Complete Table 1 based on this experiment.Lengkapkan jadual 1 berdasarkan eksperimen ini.

VariablePemboleh ubahMethod of handling the variableCara mengendalikan pemboleh ubah

Manipulated variablePemboleh ubah dimanipulasikan

Responding variablePemboleh ubah bergerak balas

Constant variable31 (c)

Pemboleh ubah dimalarkan

Table 1 Jadual 1

(d)State the hypothesis for this experiment Nyatakan hipotesis untuk eksperimen ini.31 (d)

_______________________________________________________________ ________________________________________________________________ ________________________________________________________________

(e)(i)Based on table 1, construct a table and record the results of the experiment which include the following aspects:. Berdasarkan Jadual 1, bina satu jadual dan rekodkan keputusan eksperimen yang ,eliputi aspek-aspek berikut. Water samples Time take for the samples to decolorize the methylene blue solution. level of water pollution using the scale 1 (least polluted) to 5 (more polluted) Sampel air Masa yang diambil bagi sampel air untuk melunturkan warna larutan metilena biru. Tahap pencemaran air menggunakan skala 1 ( paling kurang tercemar) hingga 5 (paling tercemar)

31 (e)(i)

ii)Using the data in 1 (e), draw a bar chart to show the relationship between the level of water pollution and the source of water samples.31 (e)(ii)

Menggunakan data 1 (e) (i), lukis satu carta bar untuk menunjukkan hubungan antara tahap pencemaran air dengan sampel air.

(f) Explain the relationship between the times taken for the decolourisation of methylene blue solution with the level of pollution of the water sample. Terangkan hubungan antara masa yang diambil untuk warna larutan metilena biru luntur dengan tahap pencemaran sampel air. ________________________________________________________________

________________________________________________________________31 (f)

________________________________________________________________

(g)Another student brought a sample of filthy water Y from a drain that decolourised very fast compared to the other samples. State the relationship between dissolved organic content and the time for decolourisation of methylene blue.Seorang pelajar lain membawa satu sampel air yang kotor Y dari longkang yang menyahwarnakan sangat cepat berbanding sampel lain. Nyatakan hubungan antara kandungan organik terlarut dan masa penyahwarnaan metilena biru. ________________________________________________________________31 (g)

________________________________________________________________ ________________________________________________________________[3 marks][3 markah]

(h)Based on the results of this experiment, state the meaning of biochemical oxygen demand (BOD) operationally.Berdasarkan keputusan eksperimen, nyatakan maksud keperluan oksigen biokimia (BOD) secara operasi. ______________________________________________________________31 (h)

______________________________________________________________ ______________________________________________________________[3 marks][3 markah]

(i)From the experiment carried out, arrange the water samples according to the degree of water quality from the cleanest to the most polluted. Dari eksperimen yang telah dijalankan, susunkan sampel air berdasarkan tahap kualiti air dari yang paling bersih hingga yang paling tercemar. _____________________________________________________________31 (i)

______________________________________________________________ ______________________________________________________________[3 marks][3 markah]

33Total

2. Enzyme is an organic substance which can be found in all living cells. Enzymes activity is influenced by several factors such as temperature, pH, substrate concentration and enzyme concentration. Based on the above information, design a laboratory experiment to investigate the effects of enzyme pepsin concentration on the rate of enzyme activity in hydrolysis of albumen. Your investigation must include the following aspect:

Enzim ialah sejenis bahan organik yang boleh dijumpai di dalam semua sel hidup. Aktiviti enzim dipengaruhi oleh beberapa faktor seperti suhu, pH, kepekatan substrat dan kepekatan enzim.Berdasarkan maklumat di atas, rekabentuk satu eksperimen makmal untuk menyiasat kesan kepekatan enzim pepsin terhadap kadar tindak balas enzim keatas hidrolisis albumen. Perancangan eksperiman hendaklah merangkumi aspek-aspek berikut:

Problem statementPenyataan masalah VariablesPembolehubah HypothesisHipotesis List of apparatus and materialsSenarai radas dan bahan Experimental proceduresProsedur eksperimen Presentation of dataPesembahan data[17 marks][17markah]

KERTAS SOALAN TAMAT

Disahkan oleh:______________________(PN HAYATUNNISA BINTI SAPRAN)

Disemak oleh:______________________(EN ISHAK BIN MOHAMED)

Disediakan oleh:______________________(PN ZALEHA BINTI IBRAHIM)

4551/1 2014 Hak Cipta Zaleha Ibrahim5