Chemistry IA Exemplar: How do the concentrations (0.05, 0.10, 0.15,… | RevisionDojo

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IB Chemistry SL Internal Assessment Example

How do the concentrations (0.05, 0.10, 0.15, 0.20, 0.25) 0.001 mol dm⁻³ of 100 cm³ aqueous sodium chloride solution affect the volume of hydrogen gas (cm³) collected at the cathode in the Hoffman apparatus after 5.00 0.01 minutes of electrolysis using a 10V power supply?SL

Overall Score

20/24

Criteria A: Research Design

6/6

Criteria Strands

A.1Research question context

Excellent

A.2Methodological considerations

Moderate

A.3Methodology description

Moderate

Criteria Feedback

You posed a focused and experimentally workable question with clear variables, a fixed time, and a specific electrochemical context.
You identified several relevant controls and practical considerations, including solution concentration, volume, apparatus, and replication.
Your method is detailed enough that another student could broadly follow the procedure and understand how the solutions were prepared.

The rationale would be stronger if it more clearly explained why this apparatus and setup are the best way to test the question.
Some methodological claims are inconsistent, especially around whether current was controlled or expected to vary.
A few procedural details remain ambiguous, such as the exact gas-measurement approach, electrode dimensions, separation, and precise volume preparation.

Criteria B: Data Analysis

5/6

Criteria Strands

B.1Communication of data recording and processing

Good

B.2Consideration of uncertainties

Moderate

B.3Data processing quality

Poor

Criteria Feedback

Your raw and processed data are organized clearly and include units, headings, and repeated trials.
You made a visible effort to process the results using means, half-range uncertainty, error bars, and a best-fit line.
The graph communicates the overall positive relationship between concentration and gas volume quite well.

The handling of an anomalous value is not justified objectively, which weakens the reliability of the processed mean.
There is a serious inconsistency in the gradient value and its interpretation, including a factor-of-ten error and unit confusion.
Your uncertainty treatment is incomplete because the analysis does not fully propagate key sources of error or show how the gradient uncertainty was derived from the worst-fit lines.

Criteria C: Conclusion

4/6

Criteria Strands

C.1Conclusion relevance and support

Moderate

C.2Scientific context comparison

Moderate

Criteria Feedback

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Criteria D: Evaluation

5/6

Criteria Strands

D.1Methodological weaknesses

Moderate

D.2Suggested improvements

Good

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...

Overall Score

20/24

Criteria A: Research Design

6/6

Criteria Strands

A.1Research question context

Excellent

A.2Methodological considerations

Moderate

A.3Methodology description

Moderate

Criteria Feedback

You posed a focused and experimentally workable question with clear variables, a fixed time, and a specific electrochemical context.
You identified several relevant controls and practical considerations, including solution concentration, volume, apparatus, and replication.
Your method is detailed enough that another student could broadly follow the procedure and understand how the solutions were prepared.

The rationale would be stronger if it more clearly explained why this apparatus and setup are the best way to test the question.
Some methodological claims are inconsistent, especially around whether current was controlled or expected to vary.
A few procedural details remain ambiguous, such as the exact gas-measurement approach, electrode dimensions, separation, and precise volume preparation.

Criteria B: Data Analysis

5/6

Criteria Strands

B.1Communication of data recording and processing

Good

B.2Consideration of uncertainties

Moderate

B.3Data processing quality

Poor

Criteria Feedback

Your raw and processed data are organized clearly and include units, headings, and repeated trials.
You made a visible effort to process the results using means, half-range uncertainty, error bars, and a best-fit line.
The graph communicates the overall positive relationship between concentration and gas volume quite well.

The handling of an anomalous value is not justified objectively, which weakens the reliability of the processed mean.
There is a serious inconsistency in the gradient value and its interpretation, including a factor-of-ten error and unit confusion.
Your uncertainty treatment is incomplete because the analysis does not fully propagate key sources of error or show how the gradient uncertainty was derived from the worst-fit lines.

Criteria C: Conclusion

4/6

Criteria Strands

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 Strands

D.1Methodological weaknesses

Moderate

D.2Suggested improvements

Good

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.