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ChemistryAssessment ObjectivesDemonstrate knowledge and understanding of:facts, concepts and terminologymethodologies and techniquescommunicating scientific information.Apply:facts, concepts and terminologymethodologies and techniquesmethods of communicating scientific information.Formulate, analyse and evaluate:hypotheses, research questions and predictionsmethodologies and techniquesprimary and secondary datascientific explanations.Demonstrate the appropriate research, experimental, and personal skills necessary to carry out insightful and ethical investigations.SL Assessment OutlineAssessment componentWeightingPaper 120%Paper 240%Paper 320%Internal Assessment20%HL Assessment outlineAssessment componentWeightingPaper 120%Paper 236%Paper 324%Internal Assessment20%SL External Assessment detailsPaper 1Duration: 3/4 hour 30 multiple-choice questions on core, about 15 of which are common with HL.The questions on paper 1 test assessment objectives 1, 2 and 3.The use of calculators is not permitted.Students will be provided with a periodic table.No marks are deducted for incorrect answers.Example exam questions.Chemistry Standard Level Paper 1. Which graph shows the Maxwell-Boltzmann energy distribution of a same amount of a gas at two temperatures, where T2 is greater than T1?The equations below represent reactions involved in the Winkler method for determining the concentration of dissolved oxygen in water:What is the amount, in mol, of thiosulfate ions, needed to react with the iodine, I2(aq), formed by 1.00 mol of dissolved oxygen?A. 2.00B. 3.00C. 4.00D. 6.00Which is propyl propanoate?A. CH3CH2CH2OOCCH2CH3B. CH3CH2CH2COOCH2CH3C. CH3CH2CH2COCH2CH3D. CH3CH2CH2OCH2CH2CH3Paper 2Duration: 1? hours Short-answer and extended-response questions on core material.The questions on paper 2 test assessment objectives 1, 2 and 3.The use of calculators is permitted. (See calculator section on the OCC.)A chemistry data booklet is to be provided by the school.Example exam questions.Chemistry Standard Level Paper 2. The biopharmaceutical industry is now a global contributor to the world economy.(a) Atorvastatin, a drug used to lower cholesterol, recently gained attention from the global media.Atorvastatin has the structure shown below.(b) Bute, a painkiller used on horses, has caused widespread concern recently becauseanalytical tests showed that it entered the food chain through horse meat labelled as beef.The drug is suspected of causing cancer.(i) Analysis of a sample of bute carried out in a food safety laboratory gave thefollowing elemental percentage compositions by mass:(ii) The molar mass, M, of bute, is 308.37 g mol–1. Calculate the molecular formula. (1)(iii) Deduce the degree of unsaturation (index of hydrogen deficiency – IHD) of bute. (1)(iv) The infrared (IR) spectrum of bute is shown below.Using information from section 26 of the data booklet, identify the bondscorresponding to A and B. (1)A:B:(v) Based on analysis of the IR spectrum, predict, with an explanation, one bondcontaining oxygen and one bond containing nitrogen that could not be present inthe structure. (2)Bond containing oxygen not present in structure:Bond containing nitrogen not present in structure:Explanation:(c) An alcohol, X, of molecular formula C3H8O, used as a disinfectant in hospitals, has the following 1H NMR spectrum.The three peaks in the 1H NMR spectrum of X have chemical shift values centred at δ = 4.0, 2.3 and 1.2 ppm.(i) From the integration trace, estimate the ratio of hydrogen atoms in differentchemical environments. (1)(ii) Deduce the full structural formula of X.(iii) Y is an isomer of X containing a different functional group. State the condensed structural formula of Y.(iv) Compare and contrast the expected mass spectra of X and Y using section 28 of the data booklet. (2)One similarity:One difference:(v) Both X and Y are soluble in water. Deduce whether or not both X and Y showhydrogen bonding with water molecules, representing any hydrogen bondingpresent by means of a diagram. (2)(vi) X reacts with acidified potassium dichromate(VI) solution to form Q and withethanoic acid to form W. Deduce the condensed structural formula of Q and W. (2)Q:W:(vii) Apply IUPAC rules to state the name of compound Q. (1)Paper 3Duration: 1 hourThis paper will have questions on core and SL option material.Section A: one data-based question and several short-answer questions on experimental work.Section B: short-answer and extended-response questions from one option.The questions on paper 3 test assessment objectives 1, 2 and 3.The use of calculators is permitted. (See calculator section on the OCC.)A chemistry data booklet is to be provided by the school.Example exam question.Chemistry Standard Level Paper 3. Section A(a) (i) Explain why the values for ODP and GWP have no units. (1)(ii) By making reference to the chemical formulas and ODP values of the compounds, comment on the hypothesis that chlorine is responsible for ozone depletion. (1)(b) Use data from the table to interpret the relationship between the atmospheric lifetime of a gas and its GWP. (2)Section BHL Assessment OverviewHL Paper 1Duration: 1 hourWeighting: 40 multiple-choice questions on core and AHL, about 15 of which are common with SL.The questions on paper 1 test assessment objectives 1, 2 and 3.The use of calculators is not permitted.Students will be provided with a periodic table.No marks are deducted for incorrect answers.Example exam question.Chemistry Higher Level Paper 1. Which electronic transition would absorb the radiation of the shortest wavelength?Which is the electron configuration of the ion Fe2+?A. 1s2 2s2 2p6 3s2 3p6 3d6B. 1s2 2s2 2p6 3s2 3p6 3d6 4s2C. 1s2 2s2 2p6 3s2 3p6 3d4 4s2D. 1s2 2s2 2p6 3s2 3p6 3d5 4s1When 0.46 g of ethanol is burned under a water-filled calorimeter, the temperature of 500 g of water is raised by 3.0 K. (Molar mass of ethanol = 46 g mol–1; specific heat capacity of water = 4.18 J g–1 K–1; q = mcΔT.)What is the expression for the enthalpy of combustion, ΔHc, in kJ mol–1?HL Paper 2Duration: 2? hoursShort-answer and extended-response questions on the core and AHL material.The questions on paper 2 test assessment objectives 1, 2 and 3.The use of calculators is permitted. (See calculator section on the OCC.)A chemistry data booklet is to be provided by the school.Example exam question.Chemistry Higher Level Paper 2. Two IB students carried out a project on the chemistry of bleach.(a) The bleach contained a solution of sodium hypochlorite, NaClO (aq). The students determined experimentally the concentration of hypochlorite ions, ClO–, in the bleach:Experimental procedure:? The bleach solution was first diluted by adding 25.00 cm3 of the bleach to a 250 cm3 volumetric flask. The solution was filled to the graduation mark with deionized water.? 25.00 cm3 of this solution was then reacted with excess iodide in acid.? The iodine formed was titrated with 0.100 mol dm–3 sodium thiosulfate solution,Na2S2O3(aq), using starch indicator.The following data were recorded for the titration:(i) Calculate the volume, in cm3, of 0.100 mol dm–3 Na2S2O3(aq) required to react with the iodine to reach the end point. (1)(ii) Calculate the amount, in mol, of Na2S2O3(aq) that reacts with the iodine. (1)(iii) Calculate the concentration, in mol dm–3, of hypochlorite ions in the dilutedbleach solution. (1)(iv) Calculate the concentration, in mol dm–3, of hypochlorite ions in the undiluted bleach solution. (1)(b) Some of the group 17 elements, the halogens, show variable valency.Deduce the oxidation states of chlorine and iodine in the following species. (1)Deduce, with a reason, the oxidizing agent in the reaction of hypochlorite ions with iodide ions in part (a). (1)From a health and safety perspective, suggest why it is not a good idea to usehydrochloric acid when acidifying the bleach. (1)(iv) The thiosulfate ion, is an interesting example of oxidation states.The sulfur atoms can be considered to have an oxidation state of +6 on one atom and –2 on the other atom. Discuss this statement in terms of your understanding of oxidation state. (2)(c) The various changes that have been made to the definitions of oxidation and reduction show how scientists often broaden similarities to general bustion is also a redox type of reaction.With reference to the combustion reaction of methane, explore two different definitions of oxidation, choosing one which is valid and one which may be considered not valid. (2)Valid…Not valid….(d) (i) State the condensed electron configuration of sulfur.(ii) Deduce the orbital diagram of sulfur, showing all the orbitals present in the diagram.HL Paper 3Duration: 1? hours This paper will have questions on core, AHL and option material.Section A: one data-based question and several short-answer questions on experimental work.Section B: short-answer and extended-response questions from one option.The questions on paper 3 test assessment objectives 1, 2 and 3.The use of calculators is permitted. (See calculator section on the OCC.)A chemistry data booklet is to be provided by the school.Example exam question.Chemistry Higher Level Paper 3. 1 Compounds used to generate cooling in refrigerators and air-conditioning systems are known as refrigerants. A refrigerant undergoes a reversible change of state involving vaporization and condensation. The search for suitable refrigerants has occupied chemists for approximately 200 years.Previously, the most popular refrigerants were chlorofluorocarbons (CFCs), but these have been replaced first by hydrochlorofluorocarbons (HCFCs) and more recently by hydrofluorocarbons (HFCs).Some data on examples of these three classes of refrigerants are shown below.(i) Explain why the values for ODP and GWP have no units. (1) (ii) By making reference to the chemical formulas and ODP values of the compounds,comment on the hypothesis that chlorine is responsible for ozone depletion.Use data from the table to interpret the relationship between the atmospheric lifetime of a gas and its GWP.The graph shows the change in levels with time of equal masses of CO2 and CH2FCF3 introduced into the atmosphere.(iii) With reference to the graph on page 4, comment on the atmospheric lifetime ofCO2 relative to CH2FCF3, and on the likely influence of this on climate change. (2)2 DNA is the molecule that carries genetic information in nearly all cells. Two months before Watson and Crick published their paper describing the double helical nature of DNA in 1953, Linus Pauling published a suggested structure for DNA based on a triple helix. Pauling’s model, which was soon proved to be incorrect, had the phosphate groups facing into the core of the helix and the nitrogenous bases facing out.Suggest why Pauling’s model would not have been a stable structure for DNA. (2) DNA has the unusual property of being able to replicate. State the type and position of the bonds that break at the start of the replication mand terms for Assessment Objective 1: Demonstrate Knowledge and mand TermDefinitionClassifyArrange or order by class or category.DefineGive the precise meaning of a word, phrase, concept or physical quantity.DrawRepresent by means of a labelled, accurate diagram or graph, using a pencil. A ruler (straight edge) should be used for straight lines. Diagrams should be drawn to scale. Graphs should have points correctly plotted (if appropriate) and joined in a straight line or smooth curve.LabelAdd labels to a diagram.ListGive a sequence of brief answers with no explanation.MeasureObtain a value for a quantity.StateGive a specific name, value or other brief answer without explanation or mand terms for Assessment Objective 2: ApplyCommand TermDefinitionAnnotateAdd brief notes to a diagram or graph.ApplyUse an idea, equation, principle, theory or law in relation to a given problem or issue.CalculateObtain a numerical answer showing the relevant stages in the working (unless instructed not to do so).DescribeGive a detailed account.DistinguishMake clear the differences between two or more concepts or items.EstimateObtain an approximate value.FormulateExpress precisely and systematically the relevant concept(s) or argument(s).IdentifyProvide an answer from a number of possibilities.OutlineGive a brief account or mand terms for Assessment Objective 3: Formulate, analyse and evaluate:Command TermDefinitionAnalyseBreak down in order to bring out the essential elements or mentGive a judgment based on a given statement or result of a pareGive an account of the similarities between two (or more) items or situations, referring to both (all) of them pare and contrastGive an account of the similarities between two (or more) items or situations, referring to both (all) of them throughout.DeduceReach a conclusion from the information given.DemonstrateMake clear by reasoning or evidence, illustrating with examples or practical application.DeriveManipulate a mathematical relationship to give a new equation or relationship.DesignProduce a plan, simulation or model.DetermineObtain the only possible answer.DiscussOffer a considered and balanced review that includes a range of arguments, factors or hypotheses. Opinions or conclusions should be presented clearly and supported by appropriate evidence.EvaluateMake an appraisal by weighing up the strengths and limitations.ExamineConsider an argument or concept in a way that uncovers the assumptions and interrelationships of the issue.ExplainGive a detailed account including reasons or causes.Explore Undertake a systematic process of discovery.InterpretUse knowledge and understanding to recognize trends and draw conclusions from given information.JustifyGive valid reasons or evidence to support an answer or conclusion.PredictGive an expected result.ShowGive the steps in a calculation or derivation.SketchRepresent by means of a diagram or graph (labelled as appropriate). The sketch should give a general idea of the required shape or relationship, and should include relevant features.SolveObtain the answer(s) using algebraic and/or numerical and/or graphical methods.SuggestPropose a solution, hypothesis or other possible answer. ................
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