IB Chemistry SL Internal Assessment Example

The topic statement provides a clear focus but would benefit from a citation or industry context to justify the relevance in commercial quality control of carbonated beverages.

The context statistic is well cited, but you should explicitly link the 1-in-5 consumption to the significance of fizziness in consumer perception.

The chemical equation is correct, but you should explain how pressure measurement relates quantitatively to the equilibrium shown.

The informal personal reflection distracts from academic tone. Consider rephrasing to emphasize scientific motivations rather than childhood fascination.

The hypothesis description ends abruptly and lacks a clear statement of the expected direction for pressure change. Complete the sentence and link to measurable parameters.

The research question is stated clearly within the context of your variables and concentrations, providing a focused investigable aim.

The controlled-variable rationale for sugar solution concentration is incomplete. Explain how the 2:1 protocol ensures precise percent values.

Uncertainty for the independent variable is stated, but justification of ±0.05 mL error must reference measurement technique limitations.

Materials list is complete but missing grade or purity of sugar and carbonated water. Including supplier details would improve reproducibility.

The choice of a 40 °C bath is reasonable but lacks justification. Explain why this temperature was selected relative to room temperature solubility.

Simultaneous use of three sensors enhances efficiency but introduces timing ambiguity. Describe how cork insertion timing was standardized.

The mixture-preparation table is clear but uses inconsistent notation (e.g., “|3.0”). Use uniform formatting for all volumes.

A typo lists 14.17 % instead of 4.17 %. Correcting concentration labels is critical for accurate interpretation.

Outlier in the 0 % trial (0.06034 kPa/s) is substantially higher. Discuss whether this reflects experimental variability.

Percentage uncertainties show inconsistent significant figures (e.g., 6.38 % vs. 20.08 %). Align with standard rules for sig. figs.

Uncertainty propagation is described for spread but neglects sensor error contribution to rate. Incorporate ±4 kPa into rate uncertainty calculation.

Graph is well labeled but would benefit from error bars to represent uncertainties in rate measurements.

The conclusion text contains contradictory statements about hypothesis support. Ensure consistency between hypothesis and final claims.

The conclusion claims linear increase in solubility despite R² = 0.65. This overstates the trend; revise to reflect correlation strength.

Methodological weaknesses are identified but not ranked by impact. Discuss which limitation most influenced your results.

The evaluation describes errors but does not link how proposed improvements would mitigate each. Provide a clear plan for addressing measurement timing and bubble issues.