PEPERIKSAAN IJAZAH SARJANA MUDA SAINS DENGAN PENDIDIKAN EXAMINATION FOR THE DEGREE OF BACHELOR OF SCIENCE WITH EDUCATION

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1 UNIVERSITI MALAYA UNIVERSITY OF MALAYA PEPERIKSAAN IJAZAH SARJANA MUDA SAINS DENGAN PENDIDIKAN EXAMINATION FOR THE DEGREE OF BACHELOR OF SCIENCE WITH EDUCATION SESI AKADEMIK 2016/2017 : SEMESTER 1 ACADEMIC SESSION 2016/2017 : SEMESTER 1 SCES2245 : PENGENALAN KEPADA KIMIA ANALISIS INTRODUCTION TO ANALYTICAL CHEMISTRY Dis 2016/ Jan 2017 Dec 2016/ Jan 2017 MASA : 2 jam TIME : 2 hours ARAHAN KEPADA CALON : INSTRUCTIONS TO CANDIDATES : Kertas soalan ini mengandungi Bahagian A dan B. This paper consists of Section A and B. Jawab soalan mengikut arahan yang diberikan dalam setiap bahagian. Answer the questions according to the instructions given in each section. (Kertas soalan ini mengandungi 6 soalan dalam 6 halaman yang dicetak) (This question paper consists of 6 questions on 6 printed pages)

2 BAHAGIAN A (50 MARKAH) SECTION A (50 MARKS) Jawab semua soalan daripada bahagian ini. Answer all questions from this section. 1. (a) Pemisahan fasa bergantung kepada analit yang lebih larut dalam salah satu daripada pelarut tak terlarutcampur atau fasa pegun di mana pengekstrakan boleh dilakukan ke fasa tersebut pada kecekapan tinggi. Nyatakan tiga contoh pemisahan fasa. Phase separations rely on the analyte being more soluble in one of the immiscible solvents or an immobilized phase and so being extracted into that phase at high efficiency. State three examples of phase separation. (6 markah/marks) Cl 2 mempunyai D = 10 antara air dan CCl 4 Cl 2 has D = 10 between water and CCl 4 (i) Kira peratus yang diekstrak dari 100 ml akueus Cl 2 ke dalam 50 ml CCl 4 Calculate the percentage extracted from 100 ml of aqueous Cl 2 into 50 ml of CCl 4 (ii) Kira peratus yang diekstrak dari 100 ml akueus Cl 2 ke dalam 500 ml CCl 4 Calculate the percentage extracted from 100 ml of aqueous Cl 2 into 500 ml of CCl 4 Diberi/Given: p = D D+( V aq Vorg ) (8 markah/marks) 2. (a) Gas kromatografi adalah kaedah analisis yang paling penting bagi sebatian yang meruap. Labelkan (i) (v) komponen penting dalam susun atur alat GC seperti yang ditunjukkan di bawah. Gas chromatography is one of the most important analytical methods for volatile compounds. Label (i) - (v) the important components in GC instrument layout as shown below. 2/6

3 (ii) (iv) (v) Two-Stage pressure regulator Flow controller Carrier gas supply Detector Injector Flow splitter Column Electric or bridge ADC (i) Column-oven (iii) (5 markah/marks) Bincangkan fungsi utama suatu larutan penimbal dan terangkan bagaimana larutan penimbal boleh disediakan. Discuss the main function of a buffer solution and explain how buffer solution may be prepared. (13 markah/marks) 3. (a) Berikan dua kelebihan penggunaan ligan multidentat (4-6 atom penderma) sebagai titran dalam pentitratan kompleksometrik. Give two advantages of using multidentate ligands (4-6 donor atoms) as titrants in complexometric titration. (6 markah/marks) Huraikan jenis membran ISE umumnya digunakan dan berikan empat contoh Elektrod Ion Tentu (termasuk penggunaan). Describe the types of ISE membrane generally used and give four examples of commercial Ion Selective Electrodes (including their usage). BAHAGIAN B (50 MARKAH) (12 markah/marks) 3/6

4 Jawab SEMUA soalan dalam bahagian ini. Answer ALL questions in this section. SECTION B (50 MARKS) 4. (a) Nyatakan perbezaan antara sebutan berikut: State the difference between the following terms: (i) (ii) (iii) (iv) (v) Analit dan sampel Analyte and sample Sampel kosong dan sampel replikat Blank sample and replicate sample Ketepatan dan kejituan Accuracy and precision Ralat tentu dan ralat tak tentu Determinate error and indeterminate error Peralatan alur-tunggal dan alur-ganda dua bagi pengukuran keserapan Single-beam and double-beam instruments for absorbance measurements (15 markah/marks) Kepekatan plumbum dalam air buangan industri ialah 0.28 ppm (berat/isipadu). Hitung kepekatan molarnya. (Diberi jisim molar Pb = g) The concentration of lead in an industrial wastewater is 0.28 ppm (weight/volume). Calculate its molar concentration. (Given molar mass Pb = g) (2 markah/marks) (c) Satu larutan stok kalium iodida, KI, mengandungi 96.3 g KI per liter larutan. Ketumpatan larutan ini ialah g ml 1 pada 20 C. Hitung kepekatan larutan ini dalam % (w/w) pada 20 C. A stock solution of potassium iodide, KI, contains 96.3 g of KI per liter of solution. The density of the solution is g ml 1 at 20 C. Calculate the concentration of the solution in % (w/w) at 20 C. (3 markah/marks) 4/6

5 5. (a) Nyatakan hukum Beer. State Beer s law. Terangkan secara ringkas penyebab kepada sisihan daripada hukum Beer. Briefly describe the causes for deviations from Beer s law. (10 markah/marks) Lakar dan labelkan gambarajah blok UV-Vis spektrofotometer. Terangkan fungsi setiap komponen utama peralatan ini. Sketch and label a block diagram of a UV-Vis spectrophotometer. Describe the function of each basic component of this instrument. (10 markah/marks) 6. Keputusan berikut diperolehi dalam penentuan kuprum dalam suatu sampel tanah dalam mg/l: The following results were obtained in the determination of copper in a soil samples in mg/l: (a) Tentukan min, sisihan piawai dan sisihan piawai relatif bagi keputusan di atas. Determine the mean, standard deviation and relative standard deviation for the above results. (5 markah/marks) Selepas enam bulan, kajian kandungan kuprum ke atas sampel tanah diulangi. Nilai purata ialah ( ) ppm bagi 6 sampel replikat. Adakah terdapat perbezaan bererti antara dua set data pada aras keyakinan 95%? After six months, the study on copper content in soil samples was repeated. The mean value was ( ) ppm for 6 replicate samples. Is the difference between the two sets of data significant at the 95% confident level? (5 markah/marks) 5/6

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