2009 HSC Chemistry Marking Guidelines

Transcription

1 009 HSC Chemistry Marking Guidelines Section I Question Correct Response C C D 4 C 5 A 6 D 7 B 8 A 9 C 0 B D A B 4 B 5 A

2 Section I, Part B Question 6 (a) Outcomes assessed: H Identifies appropriate name of reactants (alkanol+alkanoic acid) and catalyst (concentrated sulfuric acid) Provides either the features of method, including reflux, or draws diagram Identifies ONE relevant safety precaution Gives any TWO of the above Identifies any TWO of alkanoic acid, alkanol and sulfuric acid Identifies method is reflux(ing) Identifies condenser is required Identifies a relevant safety precaution

3 Question 7 Outcomes assessed: H, H4, H, H4 Identifies water and ethanol are polar molecules that form hydrogen bonds which can dissolve polar substances Identifies ethanol forms dispersion forces, therefore a good solvent for 4 both polar and non-polar substances Draws correct diagram showing hydrogen bonds for both molecules TWO of the above Identifies both water and ethanol are polar molecules that form hydrogen bonds States water dissolves polar substances, ethanol dissolves polar and nonpolar Draws correct diagram for both molecules Identifies water or ethanol as a polar molecule Identifies ethanol as a polar and non-polar molecule Draws correct diagram for one molecule

4 Question 8 Outcomes assessed: H4, H8, H6 Provides sources of evidence of increase and reason for monitoring Provides sources of oxides of nitrogen Provides balanced relevant equations Describes TWO or more effects of oxide of nitrogen in the atmosphere Provides a clear judgement based upon the above criteria Describes TWO or more effects of oxide of nitrogen in the atmosphere AND EITHER Provides relevant equations Provides sources of NO leading to ONE effect Provides evidence for the increase Identifies ONE oxide of nitrogen, eg NO Identifies ONE effect, eg photochemical smog Identifies the industrial revolution and more cars have led to increased combustion and more nitrogen oxides Identifies a piece of evidence to support increase ONE relevant equation 4 5 4

5 Question 9 Outcomes assessed: H9, H, H4 Indicates all of the main chemical and physical processes from a raw material to a monomer to polymer to finished product from natural raw material Demonstrates a thorough knowledge of the chemistry involved using relevant chemical equations Presents in a logical and coherent manner Indicates some of the main chemical and physical processes involved in the production of the finished product from natural raw material Demonstrates knowledge of some of the chemistry involved using chemical equations Indicates a feature in the manufacturing process of an identified product and provides an appropriate word equation Indicates TWO features in the manufacturing process of identified product Provides ONE correct formula and ONE feature of the manufacturing process Provides a structural formula for a monomer and corresponding polymer Indicates a feature in the manufacturing process of an identified product Provides an appropriate word equation Provides an appropriate structural formula

6 Question 0 (a) Outcomes assessed: H Correctly calculates the mass of ethanol burnt Correctly calculates q Correctly calculates the mass of ethanol WITHOUT consideration of heat loss not accounted for Uses THREE correct steps with incorrect answer(s) Correctly calculates q with correct units Incorrectly calculates mass and/or moles but demonstrates understanding of heat loss in calculation Uses TWO correct steps with incorrect answers Question 0 (b) Outcomes assessed: H States TWO appropriate ways to limit heat loss 6

7 Question (a) Outcomes assessed: H, H4 Relates ph of equivalence point to the nature of each acid correctly Relates concentration to amount of base used One of the above for both acids States strong, less concentrated acid Acid States weak, more concentrated acid Acid Identifies strength of one acid correctly Identifies relative concentration of one acid correctly Identifies equivalence point of either acid correctly States that Acid uses more base than Acid Question (b) Outcomes assessed: H8, H0 Correctly identifies the alkaline salt by name or formula relative to part (a) Question (c) Outcomes assessed: H, H Correctly calculates hydrogen ion concentration with correct units Question (d) Outcomes assessed: H0 Correctly relates colour change range for phenolphthalein to equivalence point or inflexion point on graph or vertical section of curve 7

8 Question (a) Outcomes assessed: H0, H Gives correctly balanced equations Gives one correctly balanced equation Question (b) Outcomes assessed: H0, H, H Correctly calculates moles of HCl Question (c) Outcomes assessed: H0, H, H Correctly calculates moles of NH Correctly calculates total moles HCl Question (d) Outcomes assessed: H, H, H4 Correctly calculates % of N to three significant figures Correctly calculates mass of N using moles of NH in Part (c) Correctly calculates %N to incorrect number of significant figures Correctly calculates % N with incorrect mass of N 8

9 Question Outcomes assessed: H, H4 Recognises and gives reasons for changes at 4 mins, 0 mins and 4 mins 5 6 Recognises and gives reasons for changes at two of three times 4 Recognises and gives reasons for changes at one of three times Recognises changes at three times Recognises horizontal lines indicate equilibrium has been achieved Gives a cause for one change 9

10 Question 4 Outcomes assessed: H, H Demonstrates thorough knowledge and understanding of the principles of AAS and its environmental applications Includes a relevant fully labelled diagram Demonstrates a sound knowledge and understanding of the principles of AAS and its environmental applications Includes a relevant diagram Demonstrates a basic knowledge of the principles of AAS and its environmental applications May include a basic diagram Demonstrates a limited knowledge of the principles of AAS its environmental applications May include a basic diagram 4 5 0

11 Question 5 (a) Outcomes assessed: H, H4 Correctly calculates means Phosphate concentrations interpolated correctly Correctly calculates means Interpolation of phosphate concentrations from original absorbance Question 5 (b) Outcomes assessed: H4 States how THREE streams compare to recommended level Provides TWO different sources and how these can be elevated States how THREE streams compare to recommended level Provides any TWO sources States how THREE streams compare to recommended level Provides any TWO sources Compares two streams and provides one source Idenifies one source and cause of elevated P Question 5 (c) Outcomes assessed: H4, H4 States that elevated N or P causes eutrophication States an effect of N or P States that elevated N or P causes eutrophication States an effect of N or P

12 Question 6 (a) Outcomes assessed: H0, H Gives correct oxidation and reduction half equations Gives correct overall net ionic equation without half equations Gives correct oxidation and reduction half equations Gives correct overall net ionic equation without half equations Question 6 (b) Outcomes assessed: H7, H Correctly calculates E Question 6 (c) Outcomes assessed: H Correctly labels diagram Correctly labels metals and ions with cathode and anode reversed Correctly labels metals and ions without stating cathode and anode Question 6 (d) Outcomes assessed: H8, H Names an appropriate electrolyte

13 Section II Question 7 (a) (i) Outcomes assessed: H8 States correct use Question 7 (a) (ii) Outcomes assessed: H6, H8 Sketches in general terms extraction, roasting and contact processes Identifies catalyst and temperature requirement Correctly writes TWO balanced equations or summarises chemical reactions in words Sketches ANY TWO of extraction, roasting and contact process AND EITHER Identifies catalyst and temperature requirement Writes a correctly balanced relevant equation or summarises one chemical reaction in words Outlines any process Writes a relevant equation or summarises one chemical reaction in words Identifies the catalyst Question 7 (a) (iii) Outcomes assessed: H4, H8 Identifies TWO properties of sulfuric acid Explains how the danger is minimised for each property As above for ONE property

14 Question 7 (b) (i) Outcomes assessed: H, H Correctly writes the equilibrium constant expression Question 7 (b) (ii) Outcomes assessed: H Correctly calculates K Incorrectly calculates K with at least TWO correct steps Identifies mole ratio Question 7 (b) (iii) Outcomes assessed: H7, H8, H4 Identifies effect on both K and products and/ or reactants Identifies effect on either K or products/ reactants or pressure Question 7 (c) Outcomes assessed: H9 Identifies a property of a named emulsion States ONE use related to properties Identifies a property of a named emulsion 4

15 Question 7 (d) (i) Outcomes assessed: H8, H9, H Identifies soap as having hydrophobic (non-polar) tail and a hydrophilic polar head Shows how an emulsion forms in terms of orientation of species involved ONE of the above Question 7 (d) (ii) Outcomes assessed: H9, H0, H Correctly draws the structure and names the product Correctly names the product Correctly draws the structure 5

16 Question 7 (e) Outcomes assessed: H, H4, H, H, H4 Demonstrates thorough knowledge and understanding of the significance of each criteria used to find a suitable location for an industrial plant to produce sodium carbonate Refers to the flowchart Supported by correct chemistry Demonstrates coherence and logical progression and includes correct use of scientific principles and ideas Demonstrates sound knowledge and understanding of the significance of each criteria to find a suitable location for an industrial plant to produce sodium carbonate Refers to the flowchart Communicates some scientific principles and ideas in a clear manner Demonstrates a basic knowledge of the significance of the criteria used to find a suitable location for an industrial plant to produce sodium carbonate Refers to the flowchart Communicates ideas in a basic form using general scientific terms Demonstrates a limited knowledge of the criteria used to find a suitable location for an industrial plant to produce sodium carbonate Communicates simple ideas

17 Question 8 (a) (i) Outcomes assessed: H6 States aluminum is used in drink cans in Australia Question 8 (a) (ii) Outcomes assessed: H6, H8 Shows similarities or differences between the use and effectiveness of the three cans Relates use to coating Clearly explains the use and effectiveness for one can Outlines the use and effectiveness for three cans Identifies a coating used in tins States the coating acts as a barrier States the barrier is only effective whilst intact Identifies tin as a less reactive metal than iron Question 8 (b) Outcomes assessed: H4, H6, H8 States galvanised steel is zinc coated Identifies Zn as a passivating metal providing protective barrier States that zinc can provide electrons to iron since it is more reactive States zinc is passivating metal Zinc is more reactive than iron States galvanised steel is zinc coated 7

18 Question 8 (c) (i) Outcomes assessed: H0, H Shows the cause of rusting by correctly writing the equation for the reduction of water Correctly writing the equation for the oxidation of iron Correctly writes ONE relevant equation States that iron is oxidised as the oxygen is reduced Question 8 (c) (ii) Outcomes assessed: H8, H, H Relates reactivity of the three metals Al, Fe and Cu to their electrode potentials States consequences of galvanic coupling in terms of corrosion for both 4 types of guttering Justifies the action taken Ranks the three metals in terms of reactivity States consequences of galvanic coupling in terms of corrosion for one type of guttering Justifies the action taken TWO of below Justifies the action taken Ranks the three metals in terms of reactivity States that the more active metal will corrode when two different metals are paired Gives standard electrode potentials for the three metals 8

19 Question 8 (d) (i) Outcomes assessed: H6, H8 Shows how the electrolytic process conserves this artefact by: Stating that electrolysis is used to remove (embedded) Cl Identifying artefact is cathode (and stainless steel is anode) Outlining chemistry of process TWO of the above States Cl is removed by electrolysis Identifies artefact is cathode Outlines chemistry of process Question 8 (d) (ii) Outcomes assessed: H6, H8, H Draws a fully labelled diagram Describes the process Draws a fully labelled diagram Describes the process Draws a diagram Identifies the cathode or anode Outlines the process 9

20 Question 8 (e) Outcomes assessed: H, H, H, H7, H8 Demonstrates thorough knowledge and understanding of how the work of each scientist has led to a better understanding of electron transfer reactions Refers to the flowchart Supports by the use of an equation Demonstrates coherence and logical progression and includes correct use of scientific principles and ideas Demonstrates sound knowledge and understanding of how the work of each scientist has led to a better understanding of electron transfer reactions Refers to the flowchart Communicates some scientific principles and ideas in a clear manner Demonstrates a basic knowledge of how the work of each scientist has led to a better understanding of electron transfer reactions Refers to the flowchart Communicates ideas in a basic form using general scientific terms Demonstrates a limited knowledge of the work of the scientist(s) or an understanding of an electron transfer reactions Communicates simple ideas

21 Question 9 (a) (i) Outcomes assessed: H9 Correctly identifies a factor Question 9 (a) (ii) Outcomes assessed: H6, H8, H9 Relates denaturation to disruption of the chemical bonding forces responsible for secondary and tertiary structures of proteins Identifies the particular bonding forces disrupted Relates denaturation to disruption of the chemical bonding forces responsible for secondary and tertiary structures of proteins Identifies TWO bonding forces disrupted Question 9 (b) Outcomes assessed: H9, H4 Identifies and related colour change to enzyme activity between ph Relates dark red at ph to extent of oxidation Concludes that experiment confirms enzymes act optimally within narrow ph ranges TWO of the above States most enzymes act optimally within narrow ph ranges Relates dark red to optimal ph for enzyme activity Relates experimental colour change to enzyme activity

22 Question 9 (c) (i) Outcomes assessed: H9, H0, H Gives correctly balanced equation Gives correct ΔH ONE of the above Question 9 (c) (ii) Outcomes assessed: H9, H, H Calculates correct answer Correctly calculates answer from incorrect kj Correct method with incorrect formula mass Gives correct formula mass Calculates correct answer without correct units Question 9 (c) (iii) Outcomes assessed: H, H Calculates correct answer Calculates correct answer from incorrect kj Uses correct steps with incorrect answer Uses one step correctly Calculates correct answer without correct units

23 Question 9 (d) (i) Outcomes assessed: H6, H9 Describes structure of glycerol or gives diagram Relates solubility due to polar nature Relates viscosity due to H-bonds TWO of the above ONE of the above Question 9 (d) (ii) Outcomes assessed: H6, H9 States fatty acids have a hydrophilic end from carboxylic group States fatty acids have a hydrophobic end from hydrocarbon group States long chain fatty acids are insoluble in water Identifies triacylglycerols are esters with no O H group, therefore nonpolar not soluble in H O Identifies ONE property of both fatty acids and triacylglycerols related to solubility Identifies ONE property of either fatty acids or triacylglycerols related to solubility

24 Question 9 (e) Outcomes assessed: H, H8, H9, H, H4 Demonstrates thorough knowledge and understanding of the biochemical reactions involved in muscle cell respiration that have led to improved training programs Refers to flowchart Includes relevant chemical equations Demonstrates coherence and logical progression and includes correct use of scientific principles and ideas Demonstrates sound knowledge and understanding of biochemical reactions involved in muscle cell respiration that have led to improved training programs Refers to flowchart Includes relevant chemical equations Communicates some scientific principles and ideas in a clear manner Demonstrates a basic knowledge of biochemical reactions involved in muscle cell respiration Refers to flowchart Communicates ideas in a basic form using general scientific terms Demonstrates a limited knowledge of biochemical reactions involved in muscle cell respiration Communicates simple ideas

25 Question 0 (a) (i) Outcomes assessed: H9 Gives a correct ligand Question 0 (a) (ii) Outcomes assessed: H6, H9 Defines term polydentate Identifies donor atoms in EDTA ONE of the above Question 0 (a) (iii) Outcomes assessed: H8, H9 Identifies bonds as coordinate covalent bonds States that pairs of electrons come from the donor atoms States that these electron pairs interact with d-orbitals of transition metals TWO of the above ONE of the above 5

26 Question 0 (b) (i) Outcomes assessed: H6 Gives correct maximum number of electrons Question 0 (b) (ii) Outcomes assessed: H6, H Gives all THREE electron configurations correctly Gives correct electron configuration for excited Ca atom or Ca + ion Question 0 (c) Outcomes assessed: H6, H Provides explanation for increase in IE across a period Gives explanation on each of the drops from, 0, 8 9 EITHER Explains an irregularity within a period Explains the difference between nd period ( 0) and rd period ( 8) TWO of the above ONE of the above 6

27 Question 0 (d) (i) Outcomes assessed: H6 States that atoms can exist in an excited electronic state States that light is emitted at particular wavelengths as the electrons fall back to the ground state, to a lower energy level States these observations were the basis of Planck s Quantum Theory States that particular wavelengths correspond to specific changes in energy levels which in turn correspond to particular colours of the spectrum TWO of the above ONE of the above Question 0 (d) (ii) Outcomes assessed: H6, H Provides detailed explanation of appropriate method for analysis Gives a reason why validity might be compromised Outlines a valid method Gives ONE reason why the validity might be compromised Gives ONE valid method Gives ONE reason why the validity might be compromised 7

28 Question 0 (e) Outcomes assessed: H, H6, H9, H, H4 Demonstrates thorough knowledge and understanding of the use of pigments (with atomic number in the range of 0) and the origin of the colour at the atomic level Refers to the flowchart Demonstrates coherence and logical progression and includes correct use of scientific principles and ideas Demonstrates sound knowledge and understanding of the use of pigments (with atomic number in the range of 0) and the origin of the colour at the atomic level Refers to the flowchart Communicates some scientific principles and ideas in a clear manner Demonstrates a basic knowledge of the use of pigments and the origin of the pigment colour Refers to the flowchart Communicates ideas in a basic form using general scientific terms Demonstrates a limited knowledge of the use of pigments or the origin of the pigment colour Communicates simple ideas

29 Question (a) (i) Outcomes assessed: H6, H9, H Correctly names bond Question (a) (ii) Outcomes assessed: H6, H9 Identifies differences between,, structures clearly Identifies differences between TWO levels of structure Identifies structure and indicates possible, structures being higher level of complexity overlaid Identifies ONE level of structure Question (a) (iii) Outcomes assessed: H8, H9 Outlines electrophoresis principle States proteins in samples are subject to electrophoresis to allow comparison between known and unknown proteins Outlines principle States that proteins can be compared via electrophoresis 9

30 Question (b) (i) Outcomes assessed: H Identifies the ship responsible for spill Question (b) (ii) Outcomes assessed: H6 States each peak represents a separate component Identifies that the signal intensity is proportional to the amount of component States each peak represents a separate component Identifies that the signal intensity is proportional to the amount of component Question (c) Outcomes assessed: H, H6 Provides features of THREE components of either GLC or HPLC systems that allow for smaller sample analysis Provides features of TWO components of either GLC or HPLC systems that allow for smaller sample analysis Provides features of ONE component of either GLC or HPLC system that allows for smaller sample analysis 0

31 Question (d) (i) Outcomes assessed: H9, H Clearly details procedures in a logical order Compares chromatogram for identification Clearly outlines method and comparison of chromatogram for identification Clearly details procedures in a logical order Outlines method Question (d) (ii) Outcomes assessed: H8, H9 Provides features of the tests which conclusively identify each of species unambiguously Outlines more than ONE test unambiguously Outlines tests which confirm each of the species Outlines a test

32 Question (e) Outcomes assessed: H, H9, H4 Demonstrates thorough knowledge and understanding of the processes forensic scientists follow from sample collection to presenting results Refers to flowchart Demonstrates coherence and logical progression and includes correct use of scientific principles and ideas Demonstrates sound knowledge and understanding of the processes forensic scientists follow from sample collection to presenting results Refers to flowchart Communicates some scientific principles and ideas in a clear manner Demonstrates a basic knowledge of the processes forensic scientists follow Refers to the flowchart Communicates ideas in a basic form using general scientific terms Demonstrates a limited knowledge of some of the processes forensic scientists follow Communicates simple ideas

33 Chemistry 009 HSC Examination Mapping Grid Question Content Syllabus outcomes Section I Part A H6 9..., H H H ,.a H H , ,.d H, H , ,.a H8, H ,.c,.4b H6, H0, H, H , 9... H , ,.c H8, H H9, H 9...6, 9...5,.4b H9, H0, H ,.4b H0, H , 9...9,.4b H0, H Section I Part B , , , a d H ,.e, 4.g,h H, H4, H, H , 9...7, 9...8, 9...0, 9..., , H4, H6, H ,.d, 4.b H9, H, H4 0 (a) 9...7, 9...6,.4b H 0 (b) 9...6,.c,d,e,.a H (a) , 9...4,.c, 4.a-f H, H4 (b) , , H8, H0 (c) 9...7,.c,.4b,.d H, H (d) 9..., 9... H0 (a) 9..., ,.d H0, H (b) ,.4b,.d H0, H, H (c) ,.4b,.d H0, H, H (d) 9.4.., ,.4b,.d, 4.h H, H, H , 9...4, 9.4..,.c, 4.a-h H, H , , ,.e H, H 5 (a) , ,.c H

34 009 HSC Chemistry Mapping Grid Question Content Syllabus outcomes 5 (b) , , 4.g H4 5 (c) , , , 4.d H4, H4 6 (a) , ,.d H0, H 6 (b) ,.4b H7, H 6 (c) , ,.e H 6 (d) , ,.a H8, H Section II Question 7 Industrial Chemistry (a) (i) H8 (a) (ii) , , H6, H8 (a) (iii) H4, H8 (b) (i) ,.4b,.a H, H (b) (ii) ,.4b H (b) (iii) , , 4.d H7, H8, H4 (c) H9 (d) (i) , ,.e H8, H9, H (d) (ii) ,.d H9, H0, H (e) , , , , ,.c,.d, H, H4, H, H, H4 4.b Section II Question 8 Shipwrecks, Corrosion and Conservation (a) (i) H6 (a) (ii) H6, H8 (b) /4, /4 H4, H6, H8 (c) (i) , ,.d H0, H (c) (ii) ,.4b,.d H8, H, H (d) (i) , //4, H6, H8 (d) (ii) /,.e H6, H8, H (e) //4, , 4.b H, H, H, H7, H8, H4 Section II Question 9 The Biochemistry of movement (a) (i) , H9 (a) (ii) , H6, H8, H9 (b) , , 4.c H9, H4 (c) (i) , 9.7.9, , , ,.c,.4b H9, H0, H (c) (ii).c,.4b,.d H9, H, H (c) (iii).c,.4b,.d H, H (d) (i) H6, H9 (d) (ii) , , , H6, H9 (e) /, , , ,.d, 4.b H, H8, H9, H, H4

35 009 HSC Chemistry Mapping Grid Question Content Syllabus outcomes Section II Question 0 The Chemistry of Art (a) (i) H9 (a) (ii) , H6, H9 (a) (iii) , , H8, H9 (b) (i) , H6 (b) (ii) , ,.b H6, H (c) , , ,.c H6, H (d) (i) H6 (d) (ii) ,.c H6, H (e) , , , ,.d, 4.b H, H6, H9, H, H4 Section II Question Forensic Chemistry (a) (i) ,.c H6, H9, H (a) (ii) , H6, H9 (a) (iii) , H8, H9 (b) (i) , ,.c H (b) (ii) H6 (c) H, H6 (d) (i) ,.c H9, H (d) (ii) , H8, H9 (e) , 9.9.., 9.9.., , , 4.b H, H9, H4