EXPERIMENT GUIDE LINEName: __________________________________ (Lower 6) Academic year: 2006EXPERIMENT 1Topic: Volumetric Analysis – acid basePurpose: To determine the exact concentration of a mineral acid, HXO4, and to determine the relative atomicmass of the element X.Materials: KA1 (a mineral acid, HXO4) - KA2 (a solution containing 1.70 g of OH ions per dm3 Phenolphtalein as indicatorApparatus: One 25 cm3 pipette and pipette filler Three titration flasks One 50 cm3 burette One retort stand and clamp One white tile One wash bottle filled with distilled waterProcedure: 25.0 cm3 of KA2 is pipetted into a titration flask. Two or three drops of phenolphtalein indicator are added to KA2. KA2 solution and phenolphtalein indicator is titrated with KA1. Readings are recorded in the table below. The titration is repeated 3 times to achieve accurate results.Results: Accurate Titration number Rough 1 2 3 3 Final reading (cm ) Initial reading (cm3) Volume of KA1 (cm3) 24.50- 24.90 25.00 ± 0.2 25.00 ± 0.2 25.00 ± 0.2Calculate your average titre value showing the suitable titre valuesthat you use. Fill in your answer in the blanks in the following. Skill B (6 marks):Show all steps. (a) /2e.g.: Average titre value = ……………………….. = 25.0 cm3 (b) /225.0 cm3 of KA2 required ………………… cm3 of KA1 for a complete reaction. (c) /2Analysis:1. Calculate the concentration, in mol dm–3, of solution KA2. Ans: 0.10 mol dm–32. Write a balanced ionic equation for the reaction between solution KA1 and KA2.3. Calculate the concentration, in mol dm–3, of mineral acid HXO4, in solution KA1. Skill C (6 marks): –3 Ans: 0.10 mol dm4. If the concentration of mineral acid HXO4, in solution KA1 is 10.05 g dm–3, calculate the relative molecular mass of HXO4. Ans: 100.5 g mol–15. Using the answer to Question 4, determine the relative atomic mass ofelement X. Ans: 35.5 g mol–1
6. Suggest an identity for element X. Ans: Chlorine, ClConclusion:1. Mineral acid HXO4, in solution KA1 is …………….. mol dm–3.2. The relative atomic mass of element X is ……………………… g mol–13. Therefore, KA1 is ………………….
SIJIL TINGGI PERSEKOLAHAN MALAYSIA (STPM) YEAR 2008/ 2009 SCHOOL-BASED ASSESSMENT OF PRACTICAL CHEMISTRY (PAPER 962/3)Name of school: SMK Kai Chung Centre number/ Index number: YFB 6301 /_____________Name of student: ______________________________Identity card number: ___________________________ Experiment Mark for skill tested Date Notes number A B C D E 1 2 3 5 6 9 10 11 12 13 14 15 17 19 20 Total Overall total markDECLARATION 1:I declare that the marks and information recorded above are true.Signature of teacher 1: ______________________ Name: Yeo Eng HockSignature of teacher 2: ______________________ Name: Ung Hie HuongSignature of teacher 3: ______________________ Name: ________________________DECLARATION 1:I confirm that the above declaration is true.Signature of Principal: ______________________ Date:Official stamp:
SCHOOL-BASED ASSESSMENT OF STPM PRACTICAL CHEMISTRY EXPERIMENT REPORT 2006/ 2007NAME OF SCHOOL: SMK KAI CHUNG CENTRE NUMBER: YFB 6301