| Code | Criterion | AI | Justification |
|---|---|---|---|
| RD1 | The research topic is an appropriate Chemistry level for the IB DP Chemistry and abides by the IB DP Guidance of “Asking… | 0 | The research topic fails criterion RD1. The effect of pH on iron content/solubility is explicitly covered in standard chemistry textbooks and IB curri |
| RD10 | Quantitative Independent Variable (IV) choice of values is justified. | 0 | The student lists pH values (3,5,7,9,11) but provides no explicit justification for WHY these specific values were chosen. While they discuss pH effec |
| RD11 | Quantitative Independent Variable (IV) to be manipulated is increased sequentially by intervals of equal values. Any dev… | 0 | The pH levels (3, 5, 7, 9, 11) do not follow equal intervals - the intervals are 2, 2, 2, 2 pH units respectively, which appears equal. However, pH is |
| RD12 | Quantitative Dependent Variable (DV) to be measured is stated consistently when referenced throughout the report. | 0 | The dependent variable is inconsistently stated throughout the report. Initially described as 'Iron (III)Thiocyanate content', later as 'Iron(III) thi |
| RD13 | Quantitative Dependent Variable (DV) to be measured has correct units stated. | 1 | The quantitative dependent variable is clearly identified as 'The volume of potassium permanganate (KMnO₄) required to reach the titration end-point ( |
| RD14 | Quantitative Dependent Variable (DV) is described and the chemistry is accurate. | 0 | The dependent variable description contains significant chemical inaccuracies. The student claims to measure 'Iron(III)Thiocyanate content' but the me |
| RD15 | Quantitative Dependent Variable (DV) choice of measurements is justified and the chemistry is accurate. | 0 | The student fails to provide clear justification for why measuring KMnO₄ volume is the best method to achieve their experimental objective of determin |
| RD16 | All Controlled Variables (CV) are identified in a table, with no obvious omissions. | 0 | The controlled variables table is present but has critical omissions. Missing controlled variables include: mass of spinach used (mentioned as 50g in |
| RD17 | Stating in a Controlled Variables table (CV) relevant to this study, with a column identifying the 'Value Maintained'. | 0 | The controlled variables table lacks a 'Value Maintained' column as required. While controlled variables are listed with reasons and methods, specific |
| RD18 | Stating in a table Controlled Variables (CV) relevant to this study, with a column for the 'Potential Effects'. | 0 | The student provides a controlled variables table but lacks proper 'Potential Effects' explanations. While they list reasons for controlling variables |
| RD19 | Stating in a table Controlled Variables (CV) relevant to this study, with a column for the 'Method of Control'. | 1 | The student provides a comprehensive table with controlled variables clearly listed alongside their methods of control. The table includes more than t |
| RD2 | Aim is focused in its breadth, investigating at a single relationship. | 0 | The aim is not focused on a single relationship. The research question investigates "different levels of pH (3,5,7,9,11) on the Iron (III)Thiocyanate |
| 📷 RD20 | Provide a labelled and assembled apparatus diagram that accurately allows measurement as described in the method. (chemi… | 0 | The diagram is incomplete and unclear. While it shows basic titration setup components (burette, clamp, flask, stirrer), several critical elements are |
| RD21 | All Equipment, sizes, absolute uncertainties, and amounts required for the experiment are listed or stated in the Equipm… | 0 | Equipment list missing critical items mentioned in methodology: laboratory blender, scissors, funnel, test tube, magnetic stirrer, burette clamp, ring |
| RD22 | Described the trial runs and giving details of initial problems specific to this experiment, justifying modifications wh… | 1 | The student clearly describes trial runs and initial problems. They identified that 0.001M KMnO4 was too concentrated, making differences between pH l |
| RD23 | 3rd person, past tense, step-by-step method to carry out the investigation. | 0 | The method fails multiple criteria requirements. It uses first person ('I') in steps 1 and 16 instead of third person throughout. Present tense appear |
| RD24 | Method has sufficient procedural fine detail to ensure all variables are controlled and the user can reproduce exact dat… | 0 | Critical procedural gaps prevent replication: Step 8 states adding distilled water to make 1000 cm³ in a 100 cm³ flask (impossible); pH solutions are |
| RD25 | Experiment is planned to contain at least five changes to the independent variable and justification given if this was n… | 1 | The experiment clearly states five distinct changes to the independent variable: pH levels 3, 5, 7, 9, and 11. These are explicitly mentioned in the r |
| RD26 | Health and Safety considerations of all reactants, products and conditions are recorded in a Risk Assessment table. | 0 | The Risk Assessment table is incomplete and inadequate. Only two hazards are listed (potassium permanganate and broken glass) with minimal safety info |
| RD27 | Risk Assessment table contains explicitly referenced CLEAPPS Hazcard numbers, referenced for specific chemicals/ concent… | 0 | The Risk Assessment table lacks explicit CLEAPSS Hazcard numbers. While the table lists hazards for potassium permanganate and glassware with safety m |
| RD28 | Risk Assessment table contains explicitly referenced CLEAPPS Hazcard numbers, referenced for specific disposal of materi… | 0 | The Risk Assessment table lists hazards for potassium permanganate and glassware with minimization strategies, but completely lacks any reference to C |
| RD3 | Aim wording is specific, so the reader knows exactly what the investigation is about. | 0 | The research question lacks precision and contains errors. It uses 'PH' instead of 'pH', mentions 'Iron (III)Thiocyanate content in the Spinacia Olera |
| RD4 | Sufficiently appropriate referenced science background affecting the Dependent Variable (DV) to allow understanding of t… | 0 | The background lacks sufficient detail about the dependent variable (KMnO4 volume in titration). While it mentions the redox reaction equation and end |
| RD5 | Sufficiently appropriate referenced science background explaining how the Independent Variable (IV) will potentially cau… | 0 | While the student identifies pH as the independent variable and provides some explanation of iron solubility at different pH levels, there is no in-te |
| RD6 | Valid hypothesis is justified by logical scientific reasoning and the chemistry is accurate and testable by the method. | 0 | The hypothesis lacks specificity about the expected DV trend. It states 'acidic pH allows more Iron(III) thiocyanate complex to form' and 'alkaline pH |
| RD7 | Quantitative 'Measurable' Independent Variable (IV) to be manipulated is stated and used consistently when referenced th… | 0 | The independent variable is inconsistently referenced throughout. It's stated as 'different levels of PH (3,5,7,9,11)' in the research question, then |
| RD8 | Quantitative Independent Variable (IV) to be manipulated has correct units stated. | 0 | The independent variable (pH) is correctly identified in multiple locations, but units are never explicitly stated. While pH is technically unitless, |
| RD9 | Quantitative Independent Variable (IV) concept is correctly applied to this specific experiment. | 0 | The student incorrectly identifies pH as the independent variable when the research question clearly states they are investigating 'different levels o |
| Code | Criterion | AI | Justification |
|---|---|---|---|
| 📷 AN1 | Sufficient raw data is recorded in a Results Table, with IV in the first column and DV repeats in subsequent columns to … | 1 | The student has provided a comprehensive raw data table with the independent variable (pH) in the first column and dependent variable repeats (Volume |
| 📷 AN10 | Qualitative observations are backed up by photographic evidence of the experiment | 0 | No photographs of the experimental process are present. Only tables of data, a graph, and an apparatus diagram are shown. There is no photographic evi |
| AN11 | Attempts are made to repeat measurements, until they are within the Instrumental Uncertainty limits set out by the appar… | 0 | While the student mentions 'Experiments were repeated 5 times' and shows multiple data points in tables, there is no explicit mention of attempting to |
| AN12 | Justification is given as to the number of repeat data measurements recorded. | 0 | While the report mentions conducting 5 trials for each pH level, there is no explicit justification for why 5 repetitions was chosen or why data colle |
| AN13 | Anomalous data points are identified in the recorded data, and removal justified. [No stdv mathematical requirement]. | 0 | The report does not identify any specific anomalous data points in the recorded data. While the raw data table shows some variation in individual meas |
| AN14 | If the experiment requires any processing through additional equations, then any necessary calculations in order to proc… | 1 | The experiment directly measures the relationship between pH (independent variable) and volume of KMnO4 used in titration (dependent variable). No add |
| AN15 | The specific 'First' chosen change in IV Value is stated, for which the subsequent raw DV data will be used to calculate… | 1 | The student clearly states they will use pH 3 as the first IV value for their worked example calculation: "For example, the mean data for pH 3 is calc |
| AN16 | Give one worked example of the 'First' IV Data Points to calculate mean average, using [Sum of Values/Number of Values= … | 1 | The student provides a complete worked example for pH 3 data: clearly identifies the data points (6.8, 6, 6.4, 6.3, 6.2), shows the sum calculation (6 |
| AN17 | Give one worked example to calculate the Uncertainty in Repeats is calculated from the 'First IV' Repeated Data Points d… | 0 | The student report does not include any worked example demonstrating the calculation of uncertainty in repeated measurements using the (Max-Min)/2 for |
| AN18 | The Significant Figures of the Uncertainty in Repeats is kept consistent with the apparatus (1 sig fig). | 0 | The student does not report uncertainties for repeated measurements with one significant figure. In the apparatus table, uncertainties are listed (±0. |
| AN19 | Calculate a Mean Average % Instrumental Uncertainty from both IV and DV data using the following formula: [Instrumental… | 0 | The student provides instrumental uncertainties in their apparatus table (±0.001g, ±0.05 cm³, ±0.02 cm³) but fails to calculate the required percentag |
| 📷 AN2 | All Raw and Processed Results tables are titled with specific detail of its content. | 0 | The raw data table lacks a proper title - it only shows column headers without a descriptive title explaining what the data represents. The processed |
| AN20 | Calculate a Mean Propagated % Instrumental Uncertainty calculated by [Mean Average IV % uncertainty + Mean Average DV % … | 0 | No propagated percentage instrumental uncertainty calculation is present in the student report. While the apparatus table lists individual uncertainti |
| AN21 | Mean Propagated % Instrumental Uncertainty is calculated using the lowest numbers of Decimal Places on any of the differ… | 0 | The student has not provided any propagated instrumental uncertainty calculations. While individual apparatus uncertainties are listed (±0.001g, ±0.05 |
| AN22 | Mean Propagated % Instrumental Uncertainty is quoted to 1 significant Figure | 0 | The report does not contain any calculation or statement of mean propagated instrumental uncertainty as a percentage. While individual instrumental un |
| 📷 AN23 | An appropriate sized, scatter graph. | 1 | The scatter graph is appropriately sized for the page with clear visibility of all data points and labels. The scale is suitable, showing pH values fr |
| 📷 AN24 | Scatter graph has a Title specifically stating the Independent and Dependent Variables been compared. | 1 | The scatter graph has a clear, specific title 'Relationship between pH of spinach on Volume of KmNo4 in cm^3' that explicitly states both the independ |
| 📷 AN25 | Scatter graph contains major grid lines. | 1 | The scatter graph clearly displays major grid lines on both the horizontal (pH) and vertical (Volume of KMnO4 in cm³) axes. These are continuous, prom |
| 📷 AN26 | Scatter graph contains labelled IV vs DV axis labels. | 1 | The scatter graph clearly shows labeled axes with the independent variable (pH) on the horizontal axis and dependent variable (Volume of KMnO4 in cm^3 |
| 📷 AN27 | Scatter graph contains IV vs DV 'Measurable' axis units. | 1 | The scatter graph clearly displays the independent variable (pH) on the x-axis and dependent variable (Volume of KMnO4) on the y-axis. Both axes are p |
| 📷 AN28 | Scatter graph contains IV vs DV axis Instrumental Uncertainty values. | 0 | The scatter graph is present with appropriate IV (pH) vs DV (Volume of KMnO4) and includes uncertainty bars for the vertical DV axis. However, there a |
| 📷 AN29 | Scatter graph contains uses crosses to plot data points. | 0 | The scatter graph uses circles/dots to plot data points instead of crosses (X marks). All data points are consistently plotted as circular symbols, wh |
| 📷 AN3 | Data table column headings include 'Measurable' units. | 0 | The data tables have critical missing units. In the first table, 'pH' lacks units (should be 'pH units' or dimensionless notation), and 'Volume of KMn |
| 📷 AN30 | A scatter graph trendline gradient equation shows the Final Relationship is given. | 1 | The scatter graph clearly shows a trendline with the gradient equation y = -0.426x + 5.07 in the standard y=mx+c format. The gradient value m = -0.426 |
| 📷 AN31 | Scatter graph trendline has a R2 value given. | 1 | The scatter graph clearly shows a trendline with an R² value of 0.9571 displayed on the graph. The coefficient of determination is visible and appears |
| 📷 AN32 | Horizontal 'Uncertainty bars' for IV are added to the scatter graph, using the IV Instrumental Uncertainty, to graphical… | 0 | The scatter graph shows vertical uncertainty bars for the dependent variable (volume of KMnO4) but completely lacks horizontal uncertainty bars for th |
| 📷 AN33 | Vertical 'Uncertainty bars' for DV are added to the scatter graph to graphically show the calculated values of the Uncer… | 1 | The scatter graph clearly shows vertical uncertainty bars on all data points representing the dependent variable (volume of KMnO4). The bars accuratel |
| 📷 AN34 | A Maximium gradient trendline is calculated from the lowest vertical uncertainty bar and highest horizontal uncertainty … | 0 | The student has not calculated maximum and minimum gradient trendlines. The graph shows only one trendline (y = -0.426x + 5.07) without demonstrating |
| 📷 AN35 | A Minimum gradient trendline is calculated from the highest vertical uncertainty bar and lowest horizontal uncertainty b… | 0 | The student has not calculated minimum and maximum gradient trendlines using uncertainty bars. The graph shows only a single best-fit line with equati |
| 📷 AN36 | Trendline equations for the Maximum and Minimum gradient trendlines are shown on the graph. | 0 | The graph shows only one trendline equation (y = -0.426x + 5.07, R² = 0.9571) representing the line of best fit through the data points. There are no |
| AN37 | Uncertainty in Final Relationship is calculated by [(Maximum gradient value-minimum gradient value)/2 = Uncertainty in F… | 0 | The student's report does not contain any calculation of 'Uncertainty in Final Relationship' using the required formula [(Maximum gradient value - min |
| AN38 | State Uncertainty in Final Relationship units, using [Y axis units/X axis units] formula. | 0 | The student does not provide an uncertainty calculation for the final relationship. While they present a linear equation (y = -0.426x + 5.07) showing |
| AN39 | State Uncertainty in Final Relationship to 1 Significant Figure | 0 | The student does not explicitly state the uncertainty of their final relationship to 1 significant figure. While they present a linear equation (y = - |
| 📷 AN4 | Data table column headings include Instrumental Uncertainties. | 0 | The data tables do not include instrumental uncertainties in column headings. While the processed data table shows an 'uncertainty' column with calcul |
| AN40 | Convert Uncertainty in Final Relationship into %Uncertainty in Final Relationship using the [Uncertainty in Final Relati… | 0 | The student did not perform the required calculation to convert uncertainty in final relationship into percentage uncertainty. While the report shows |
| AN41 | State %Uncertainty in Final Relationship to 1 Signficant Figure | 0 | The student's report does not explicitly state the percentage uncertainty of the final relationship. While the linear equation y = -0.426x + 5.07 is p |
| 📷 AN5 | Data table column headings Instrumental Uncertainties are kept to 1 significant Figure. | 0 | The data table shows an 'uncertainty' column with values that violate the one significant figure rule. Specifically, uncertainty values of '1.25' and |
| 📷 AN6 | Data tables are formatted adequately, making it easy to read. Running the table over page breaks, very small font and ve… | 0 | The data tables have significant formatting issues: extremely narrow column widths make data difficult to read, font appears too small for optimal rea |
| AN7 | All Instrumental Uncertainties from measuring devices are justified. (Analogue = Half the smallest readable digit, Digit… | 0 | The student lists uncertainties for several instruments (electronic balance ±0.001g, volumetric flask ±0.10cm³, pipette ±0.02cm³, burette ±0.05cm³, me |
| 📷 AN8 | The Decimal Points of raw and processed data are consistent with Instrumental Uncertainties on measurements | 0 | The data shows inconsistent decimal places that don't align with instrumental uncertainties. Raw titration volumes are reported to 1 decimal place (e. |
| AN9 | Qualitative observations Before, During, and After are recorded that will assist with interpretation. | 0 | No qualitative observations for Before, During, and After phases are recorded. The student mentions color changes (pale pink endpoint) but provides no |
| Code | Criterion | AI | Justification |
|---|---|---|---|
| CO1 | The research question is answered by describing the IV-DV relationship gradient trend. | 1 | The student clearly describes the IV-DV relationship with explicit gradient analysis. They state there is a 'decrease of titre volume as pH increases' |
| CO2 | The IV-DV relationship gradient equation is explicitly stated. | 1 | The IV-DV relationship gradient equation is explicitly stated in the Analysis section: 'y = -0.426x+5.07' where y represents the dependent variable (v |
| CO3 | The IV-DV relationship gradient units are quoted in the conclusion. | 0 | The conclusion does not explicitly state the gradient units. While the student mentions the linear gradient equation y = -0.426x+5.07 in the analysis |
| CO4 | Comment on gradient R2 value in terms of strength of correlation. (weak <0.3, moderate 0.3-0.7, strong >0.7) | 1 | The student clearly states the R² value as 0.9571, correctly interprets it as indicating a "very strong fit" between pH and KMnO₄ volume data, and pro |
| CO5 | Accuracy of relationship is justified based on cited research of a similar area of study. | 0 | The report lacks proper in-text citations throughout the text where chemical relationships are described. While references are listed at the end, they |
| CO6 | Hypothesis is re-stated and compared with final results and commented on in terms of trend and speculation as to the und… | 1 | The student clearly restates their hypothesis in the conclusion, explicitly comparing it with results. They confirm the hypothesis was supported: "aci |
| CO7 | % Uncertainty in Final Relationship from min-max trendlines is re-stated in the Conclusion. | 0 | The Conclusion section does not contain any percentage uncertainty values from min-max trendlines. While the student discusses the linear relationship |
| CO8 | The magnitude of the %Uncertainty in Final Relationship gradient to potentially change the trend direction and invalidat… | 0 | The student report lacks any discussion of the magnitude of uncertainty in the final relationship gradient (y = -0.426x + 5.07). There is no analysis |
| CO9 | Any concerns making the result invalid have been commented on. If the experiment has no obvious problems in its logic, l… | 1 | The student provides comprehensive commentary on major experimental concerns that could invalidate results. They identify and discuss significant issu |
| Code | Criterion | AI | Justification |
|---|---|---|---|
| EV1 | Strengths of methodology are highlighted, based on trial run modifications if possible. | 1 | The student clearly identifies multiple methodological strengths with specific explanations. They demonstrate trial-run modifications (changing KMnO4 |
| EV10 | Improvements suggested to expand the IV data range are made. | 0 | The student does not provide specific suggestions for expanding the independent variable (IV) data range with actual pH values. While they mention cha |
| EV11 | Improvements suggested to narrow the IV data intervals are made. | 0 | The student does not provide specific suggestions for narrowing IV data intervals. While they mention using pH levels 3,5,7,9,11 (intervals of 2 units |
| EV12 | Minor Methodological improvements suggested to improve on the accuracy of the experiment. | 1 | The student provides multiple specific methodological improvements with clear explanations of how they would enhance accuracy: using a colorimeter ins |
| EV13 | Suggested extension investigations, that will adapt and improve this specific investigation are proposed. | 0 | No extension investigations are proposed in the student report. The document contains methodology, results, analysis, and improvements but lacks any s |
| EV2 | Equipment choice is evaluated to reduce Instrumental Uncertainties. | 0 | The student lists equipment with uncertainties but fails to analyze how each piece contributes to combined instrumental uncertainties. They don't iden |
| EV3 | Comparison of a Mean Propagated % Instrumental Uncertainty vs % Uncertainty in Final Relationship from gradients is stat… | 0 | The student report lacks the required detailed comparison section explicitly stating the percentage propagated instrumental uncertainty based on avera |
| EV4 | Major Methodological improvements suggested to improve accuracy and validity by identifying and removing specific System… | 0 | The report identifies several systematic errors (visual endpoint detection, measuring cylinder imprecision, burette reading parallax error, time const |
| EV5 | Weaknesses in method are stated in a table with a column for discussion of ‘Relative significance', with no obvious omis… | 0 | The weaknesses are presented in a table format with clear descriptions and improvement methods, but there is no column labeled 'Relative significance' |
| EV6 | Weaknesses in method are stated in a table with a column for ‘Error Type' and are correctly identified, with Systematic … | 0 | The student provides a table with weaknesses and improvements but lacks the required 'Error Type' column. While they identify various errors, they don |
| EV7 | Weaknesses in method are stated in a table with a column for ‘Problems'. | 1 | The student provides a clear table with a 'Problems' column that identifies specific methodological weaknesses. Each entry in the Problems column clea |
| EV8 | Weaknesses in method are stated in a table with a column for ‘Suggested Solutions'. | 1 | The student provides a clear table with weaknesses in the left column (Visual Endpoint Detection, Use of Measuring Cylinder, Reading of burette volume |
| EV9 | Improvements suggest increased Repeated data points and removal of outliers to reduce Random Errors, causing smaller Unc… | 0 | The student mentions repeating experiments 5 times to minimize random errors but fails to distinguish between the two distinct processes required. The |