Chemistry IA Exemplar: What is the effect of increasing the… | RevisionDojo

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IB Chemistry SL Internal Assessment Example

What is the effect of increasing the concentration of acetone (c ± 0.1 M: 5.0, 6.0, 7.0, 8.0, 9.0, 10.0) on the rate of reaction (r ± Δr) of the iodination of acetone, catalyzed by hydrochloric acid, by the decrease in absorbance at 422.3 nm as measured by spectrophotometry?SL

Official IB Result

IB Grade: 6

Criteria A: Research Design

5/6

Criteria StrandsPro

A.1Research question context

Good

A.2Methodological considerations

Moderate

A.3Methodology description

Moderate

Criteria Feedback

The student sets the investigation in a clear, chemically meaningful context and explains why spectrophotometry is suitable for this reaction.
The student's research question is specific and focused, naming the reaction system, wavelength, method, and intended concentration range.
The student includes several practical controls and design choices, such as repeats, fixed reagent volumes, and a consistent reading procedure.

The concentration variable is not fully defined, because the prepared acetone stock concentrations are treated as if they were the concentrations in the reacting mixture.
The temperature control is not robust enough for a kinetics investigation and could still allow drift during measurements.
Some parts of the method are inconsistent or incomplete, which limits full reproducibility.

Criteria B: Data Analysis

4/6

Criteria StrandsPro

B.1Communication of data recording and processing

Good

B.2Consideration of uncertainties

Moderate

B.3Data processing quality

Moderate

Criteria Feedback

The student's raw data are organized clearly, with tables that make the repeated trials, means, and processed rates easy to follow.
The student uses graphing and regression appropriately to explore the relationship between the variables.
The student shows some real awareness of uncertainty through error bars, propagated time uncertainty, and gradient uncertainty bounds.

The x-values are based on the prepared acetone solutions rather than the final reaction-mixture concentrations, which makes the processed results internally inconsistent.
The student's uncertainty treatment does not fully account for all the important sources of error, especially the iodine concentration term and other kinetic sources of variation.
Some table labels and graph presentation choices are clear, but not always precise enough to match the numerical processing.

Criteria C: Conclusion

4/6

Criteria StrandsPro

C.1Conclusion relevance and support

Moderate

C.2Scientific context comparison

Moderate

Criteria Feedback

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Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.

Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Criteria D: Evaluation

5/6

Criteria StrandsPro

D.1Methodological weaknesses

Good

D.2Suggested improvements

Moderate

Criteria Feedback

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.

Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Loading scores...

Official IB Result

IB Grade: 6

Criteria A: Research Design

5/6

Criteria StrandsPro

A.1Research question context

Good

A.2Methodological considerations

Moderate

A.3Methodology description

Moderate

Criteria Feedback

The student sets the investigation in a clear, chemically meaningful context and explains why spectrophotometry is suitable for this reaction.
The student's research question is specific and focused, naming the reaction system, wavelength, method, and intended concentration range.
The student includes several practical controls and design choices, such as repeats, fixed reagent volumes, and a consistent reading procedure.

The concentration variable is not fully defined, because the prepared acetone stock concentrations are treated as if they were the concentrations in the reacting mixture.
The temperature control is not robust enough for a kinetics investigation and could still allow drift during measurements.
Some parts of the method are inconsistent or incomplete, which limits full reproducibility.

Criteria B: Data Analysis

4/6

Criteria StrandsPro

B.1Communication of data recording and processing

Good

B.2Consideration of uncertainties

Moderate

B.3Data processing quality

Moderate

Criteria Feedback

The student's raw data are organized clearly, with tables that make the repeated trials, means, and processed rates easy to follow.
The student uses graphing and regression appropriately to explore the relationship between the variables.
The student shows some real awareness of uncertainty through error bars, propagated time uncertainty, and gradient uncertainty bounds.

The x-values are based on the prepared acetone solutions rather than the final reaction-mixture concentrations, which makes the processed results internally inconsistent.
The student's uncertainty treatment does not fully account for all the important sources of error, especially the iodine concentration term and other kinetic sources of variation.
Some table labels and graph presentation choices are clear, but not always precise enough to match the numerical processing.

Criteria C: Conclusion

4/6

Criteria StrandsPro

C.1Conclusion relevance and support

Moderate

C.2Scientific context comparison

Moderate

Criteria Feedback

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.

Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Criteria D: Evaluation

5/6

Criteria StrandsPro

D.1Methodological weaknesses

Good

D.2Suggested improvements

Moderate

Criteria Feedback

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.

Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur.
Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.