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NB !!! VERY IMPORTANT EXAM INFORMATION   If you have answered all your questions or the time has elapsed, please click on the “Submit Quiz” button below.   Please then move on to the PHSC GR12E SBA 004b JUNE EXAMINATION PAPER 2 (PDF DOWNLOAD) QUIZ, by clicking on the “NEXT” button.   Please upload your SINGLE PDF document in this “Quiz”.   You will be given 30 minutes for the upload.   Please remember to name your PDF document correctly: NAME_SURNAME_PHSC_GR12E_SBA004b

VRAAG 8 Ammoniak is ‘n kleurlose gas wat bekend is vir sy onaangename reuk. In hoë konsentrasies word dit as giftig beskou. 8.1 Wat is die chemiese formule vir ammoniak? (2) 8.2 Hoeveel alleenpare het ammoniak? (2) 8.3 Teken ‘n Lewis-diagram van die ammoniakmolekule. (4) 8.4 Bepaal die molekulêre vorm van die chloortrifluoriedmolekule. (2) 8.5 Is dit ‘n polêre of nie-polêre molekule? Verduidelik jou antwoord. (3) [13]

1.9 Choose the correct terms to complete the following sentence: Carbon tetrafluoride is a ________ shaped molecule and is _______. (2)

INSTRUCTIONS 1. This question paper consists of SEVEN questions. Answer QUESTION 1 on the computer and QUESTION 2 to QUESTION 7 on a separate piece of paper and upload the answers in the SECOND UPLOAD QUIZ, FOLLOWING THIS QUIZ. 2. Start EACH question on a NEW page. 3. Number the answers correctly according to the numbering system used in this question paper. 4. Leave ONE line open between two sub-questions, for example between QUESTION 2.1 and QUESTION 2.2. 5. You may use a non-programmable calculator. 6. You may use appropriate mathematical tools. 7. You are advised to use the attached DATA SHEETS. 8. Show ALL formulas and substitutions in ALL calculations. 9. Round off your FINAL numerical answers to TWO decimal places. 10. Give short (concise) motivations, discussions, etc., where necessary. 11. Write neatly and legibly. 12. Please submit Section B as a SINGLE PDF File. Name the file as follows: NAME_SURNAME_GR12E_PHSC_SBA004b

1.4 Activation energy can best be described as the minimum energy required for ______. (2)

1.5 Noem die tipe intermolekulêre krag wat die volgende situasie beskryf: Die intermolekulêre krag tussen ‘n ioon en ‘n nie-polêre molekule, wat lei tot ‘n swak, kortstondige krag wat die verbindings bymekaar hou. (2)

QUESTION 5 The graph below shows the energy changes during the course of a chemical reaction.   Right click on the following blue button to open ALL THE IMAGES for QUESTION 5, in a new tab.   5.1 Define ‘activation energy’. (2) 5.2 Does the graph represent an endothermic or exothermic reaction? Motivate your answer. (2) 5.3 Write down the activation energy for the reverse reaction in kJ.mol-1 (2) 5.4 A suitable catalyst was obtained for this reaction. Redraw the given graph and clearly indicate what the effect of the catalyst will be on the activation energy. (2) 5.5 How will the addition of a catalyst affect the ΔH? (2) 5.6 The following curves suggest different factors that can influence the rate of a chemical reaction.   Please refer to Diagram 2, Question 5 to answer the following questions.   5.6.1 Which line X, Y or Z, represents an increase in the concentration of the reactants? (2) 5.6.2 Use the collision theory to explain how the increase in concentration will affect the reaction rate. (3) 5.7 A study was done to find out the effect of the concentration of a reactant on the total time it takes to complete a chemical reaction. Four attempts of the same reaction are performed. In each attempt, the initial concentration of the reactant was different. The time required to complete the reaction is measured each time. The data for each of the four attempts are shown in the table below.   Please refer to Diagram 3, Question 5 to answer the following questions.   5.7.1 Provide an investigative question for this experiment. (2) 5.7.2 Identify the dependent variable. (1) 5.7.3 Use the results in the table and draw a graph. (4) 5.7.4 Use your graph and calculate the average reaction rate for the first 40 s. (4) 5.7.5 Write a conclusion for this experiment. (2)     [28]

1.4 Kies die regte term om die volgende sin te voltooi; In ‘n nie-polêre molekule word die lading ________ oor die molekule versprei (2)

NB !!! VERY IMPORTANT EXAM INFORMATION   If you have answered all your questions or the time has elapsed, please click on the “Submit Quiz” button below.   Please then move on to the PHSC GR11E SBA 004b JUNE EXAMINATION PAPER 2 (PDF DOWNLOAD) QUIZ, by clicking on the “NEXT” button.   Please upload your SINGLE PDF document in this “Quiz”.   You will be given 30 minutes for the upload.   Please remember to name your PDF document correctly: NAME_SURNAME_PHSC_GR11E_SBA004b

1.7 Van wat is die volgende ‘n definisie: ‘n Maatstaf van die aantal botsings van die gasdeeltjies met mekaar en met die sykante van die houer waarin hulle is. (2)