IB Chemistry HL Internal Assessment Example

The introduction omits any mention of broader or industrial significance. Adding a sentence on potential applications or relevance of lowering activation energy in industry would enhance context.

The research question is clearly stated within the specific redox context, but the rationale for choosing only Copper(II) and Iron(II) catalysts over other transition metals is not explained. Including this justification would strengthen the investigation’s focus.

The balanced ionic equation is presented clearly, aiding reader comprehension of the chemical system.

Temperature range in the Aim is clear, but degree symbols and unit formatting are inconsistent. Standardize to “25 °C” etc. throughout.

The definition of a catalyst is well‐written but lacks a specific citation for the mechanism described. Include a precise reference rather than just “[6]”.

The theoretical background describes collision theory but does not explicitly link it to how rate constants were calculated from timing measurements. Draw that connection for clarity.

Typographical error “Fiugre 2” and ambiguous figure numbering undermine clarity. Correct spelling and label figures consistently.

The linearization of the Arrhenius equation is not fully explained. Show step‐by‐step algebraic manipulation when taking ln of both sides.

Equation (2) is identical to Equation (1) rather than showing the natural log transformation. Include the correct intermediate expression.

The equipment list is comprehensive, but justification for chosen tolerances and volumes (e.g. 3 cm³ pipette) is missing. Explain why these instruments were selected.

Cross‐mark dimensions and observer position are not specified in the Methodology, reducing reproducibility. State size of the cross and viewing distance.

No rationale is provided for using 1 cm³ of catalyst at 0.01 M. Clarify why this concentration and volume were chosen to ensure data sufficiency.

Independent variable section omits control of ambient lighting during timing; background contrast can affect endpoint detection. Consider standardizing illumination.

Table 1’s CuSO₄ label lacks proper subscript formatting and one CuSO₄ trial row appears to list only four values instead of five. Verify table completeness and formatting.

The initial no‐catalyst trial at 25 °C shows an outlier (29.76 s) well above other values. Discuss whether this point should be excluded or its impact assessed.

Equation (6) incorrectly states T = 1/T. The reciprocal relationship should be Δ(1/T)=1/T; correct labeling and algebra are needed.

Propagation of uncertainty for 1/T is misapplied. The correct expression is Δ(1/T)=ΔT/T²; revisit the derivation to ensure validity.

Table 4 lists Δk values but omits contributions from time measurement precision and reactant concentration uncertainties. Acknowledge and discuss these omissions.

Figure 4 lacks error bars indicating uncertainty in ln k and 1/T. Including error bars or shaded envelopes would better communicate data reliability.

The FeSO₄ activation energy is higher than the uncatalyzed case, contradicting expected catalyst behavior. Provide a deeper interpretation of this anomaly.

Units in Equation (15) are incorrect (‘kmol⁻¹’ should read ‘kJ mol⁻¹’). Ensure unit consistency throughout activation energy calculations.

Percentage error calculation uses Δm rather than ΔEₐ. Clarify that ΔEₐ = (Eₐₘₐₓ–Eₐₘᵢₙ)/2 and ensure percent error formula references Eₐ directly.

Comparison to literature values is limited to the uncatalyzed case only. Include references or values for catalyzed systems to deepen scientific context.

The conclusion restates activation energies accurately, but does not discuss how uncertainty affects confidence in the claims. Add a brief comment on uncertainty impact.

Weaknesses describe human error and temperature control but do not quantify their relative influence on activation energy results. Elaborate on which factor matters most.

No explicit section on suggested improvements is provided. Propose concrete enhancements such as automated optical detection and PID‐controlled water bath.

The reference list relies heavily on non‐peer‐reviewed online resources. Incorporate journal articles or textbooks to strengthen academic rigor.