Case Study: Unit 2 Evaluations: Personal Competencies
Assignment 2D: How Am I Doing?
Unit 2 Evaluations provide an opportunity for students to develop and assess their scientific skills
through various experiments. Let us examine the personal competencies developed and analyse the
skills acquired in each experiment, as well as suggest improvements for future practice.
2A PART 1: Titrations of sodium hydroxide and hydrochloric acid
P7: Summarise key personal competencies developed in relation to scientific skills undertaken:
Through the titrations of sodium hydroxide and hydrochloric acid, I developed the following key personal
competencies in relation to scientific skills:
- Accurate pipetting and burette reading: I acquired skills in precise measurement techniques, ensuring
the correct volumes of solutions were added during titrations.
- Endpoint detection: I learned to identify the colour change or other indicators that signal the
completion of a titration, enabling accurate determination of the concentration of the unknown solution.
- Calculation and data analysis: I developed proficiency in performing calculations based on the volume
and concentration of solutions used, allowing for the determination of unknown concentrations.
- Understanding stoichiometry: I gained a deeper understanding of the concept of stoichiometry and its
application in titration calculations.
M4: Analyse skills developed and suggest improvements to own practice.
,- Working safely: I prioritized safety by wearing appropriate protective equipment, handling chemicals
carefully, and following laboratory protocols. To improve my practice, I could familiarize myself with
safety guidelines specific to titrations and stay updated on any new safety protocols given by the teacher.
- Responsibility: I took responsibility for my work and assumed the leadership of my group by ensuring
accurate measurement and recording of data, as well as maintaining a clean and organized workspace.
To enhance my practice, I can actively contribute to discussions on improving experimental techniques
and taking ownership of collaborative projects.
- Partner feedback: Ametz provided feedback on my performance, acknowledging my careful
measurement techniques and accurate calculations. This feedback encourages me to maintain attention
to detail and precision.
- Areas for improvement: I need to further develop my skills in recognizing subtle colour changes and
accurately determining the endpoint of titrations. To achieve this, I could practice with a wider range of
indicators and collaborate with peers to gain different perspectives and insights.
2A PART 2: Colorimetry of sodium hydroxide and hydrochloric acid
P7: Summarise key personal competencies developed in relation to scientific skills undertaken:
During the colorimetry experiments involving sodium hydroxide and hydrochloric acid, I developed the
following key personal competencies in relation to scientific skills:
- Calibration of colorimeters: I acquired skills in calibrating colorimeters and ensuring accurate
measurements of absorbance.
- Preparation of standard solutions: I learned to prepare standard solutions with known concentrations,
allowing for the creation of calibration curves and the determination of unknown concentrations.
- Spectrophotometric analysis: I gained proficiency in measuring the absorbance of solutions at specific
wavelengths, providing quantitative data for analysis.
- Data interpretation: I developed the ability to interpret colorimetric data, including identifying the
relationship between absorbance and concentration and applying it to determine unknown
concentrations.
M4: Analyse skills developed and suggest improvements to own practice.
- Working safely: I followed safety guidelines while handling chemicals and operating colorimeters,
including wearing gloves and working in a well-ventilated area. To improve my practice, I could actively
seek safety information specific to colorimetry techniques and ensure proper waste disposal.
- Responsibility: I took responsibility for my work by ensuring accurate measurement and recording of
data, as well as maintaining a controlled experimental environment. To enhance my practice, I can
actively engage in discussions about optimizing experimental procedures and taking on leadership roles
in collaborative projects.
,- Partner feedback: My partners, Ametz and Ebenezer provided feedback on my performance, noting my
meticulous approach to measurement and data analysis. This feedback motivates me to maintain my
attention to detail and precision.
- Areas for improvement: I need to further develop my skills in managing potential sources of error in
colorimetry, such as variations in light intensity or contamination of cuvettes. To address this, I could
explore additional techniques for minimizing error sources, conduct more repeat measurements, and
consult with experts or resources to gain insights into error analysis and reduction.
2B: Use calorimetry of paraffin wax and stearic acid to study cooling curves
P7: Summarise key personal competencies developed in relation to scientific skills undertaken:
Using calorimetry to study cooling curves of paraffin wax and stearic acid, I developed the following key
personal competencies in relation to scientific skills:
- Calorimeter setup and operation: I acquired skills in setting up and using calorimeters to measure heat
transfer during cooling processes.
- Data collection and analysis: I learned to collect temperature data at regular intervals and analyse the
resulting cooling curves, enabling the determination of cooling rates and phase transitions.
- Heat capacity calculations: I gained proficiency in calculating the heat capacities of substances based on
their cooling curves and known masses.
- Interpretation of results: I developed the ability to interpret cooling curves and relate them to the
underlying physical processes, such as solidification or phase changes.
M4: Analyse skills developed and suggest improvements to own practice.
- Working safely: I followed safety guidelines while handling hot substances and operating calorimeters,
including using appropriate protective equipment and practicing caution to prevent accidents. To
improve my practice, I could stay updated on safety protocols specific to calorimetry experiments and
actively seek information on safe handling of substances with high heat capacities.
- Responsibility: I took responsibility for my work by ensuring accurate temperature measurements,
proper setup of the calorimeter, and reliable data recording. To enhance my practice, I can actively
contribute to discussions on optimizing experimental conditions and taking the initiative to troubleshoot
any issues that arise.
- Partner feedback: Ebenezer helped me by providing feedback on my performance, noting my attention
to detail in data collection and analysis. This feedback encourages me to maintain my meticulous
approach to experimental writeups
,- Areas for improvement: I need to further develop my skills in minimizing heat loss during calorimetry
experiments and improving the accuracy of temperature measurements. To achieve this, I could explore
insulation techniques, fine-tune the calibration of temperature sensors, and consult with experts or
resources to gain insights into heat transfer and measurement accuracy.
2C: Paper chromatography of extracted plant pigments (primrose and spinach)
P7: Summarise key personal competencies developed in relation to scientific skills undertaken:
Through the paper chromatography experiments involving primrose and spinach pigments, I developed
the following key personal competencies in relation to scientific skills:
- Sample preparation: I acquired skills in extracting plant pigments and preparing samples for paper
chromatography, ensuring the availability of suitable compounds for separation.
- Spotting techniques: I learned to spot the extracted pigments accurately on the chromatography paper,
ensuring well-defined spots for separation.
- Separation and migration analysis: I gained experience in running paper chromatography and analysing
the migration of pigments, allowing for the identification of different compounds present in the plant
extracts.
- Visualization and interpretation: I developed the ability to visualize the separated pigments and
interpret the results based on their migration distances and interactions with the chromatography paper.
M4: Analyse skills developed and suggest improvements to own practice.
- Working safely: I followed safety guidelines while handling solvents, plant extracts, and
chromatography paper, including using protective equipment and ensuring proper waste disposal. To
improve my practice, I could actively seek safety information specific to paper chromatography and stay
updated on any changes in safety protocols.
- Responsibility: I took responsibility for my work by ensuring accurate spotting, proper handling of
chromatography materials, and careful data recording. To enhance my practice, I can actively engage in
discussions about optimizing experimental procedures and contribute to the development of protocols
that improve accuracy and reproducibility.
- Partner feedback: The teacher provided feedback on my performance, noting my precise spotting
techniques and careful observation of migration patterns. This feedback motivates me to maintain my
attention to detail and focus on improving my chromatography skills.
- Areas for improvement: I need to further develop my skills in optimizing chromatography conditions for
better separation and identification of pigments. To address this, I could explore different solvent
,systems, refine spotting techniques, and seek guidance from experts or resources to gain insights into
advanced chromatography methods.
2C: TLC (Thin Layer Chromatography) chromatography of extracted plant pigments (primrose and
spinach)
P7: Summarise key personal competencies developed in relation to scientific skills undertaken:
During the TLC chromatography experiments involving primrose and spinach pigments, I developed the
following key personal competencies in relation to scientific skills:
- TLC plate preparation: I acquired skills in preparing TLC plates and ensuring the proper application of
the stationary phase (silica gel or other suitable material).
- Spotting and development: I learned to spot the extracted pigments accurately on the TLC plates and
develop them in a suitable solvent system, allowing for the separation and visualization of different
compounds.
- Rf value determination: I gained proficiency in calculating the Rf values of separated compounds,
providing a quantitative measure of their migration distance relative to the solvent front.
- Compound identification: I developed the ability to identify compounds based on their Rf values and
compare them to known standards or reference materials.
M4: Analyse skills developed and suggest improvements to own practice.
- Working safely: I followed safety guidelines while handling solvents, TLC plates, and plant extracts,
including using appropriate protective equipment and ensuring proper ventilation. To improve my
practice, I could actively seek safety information specific to TLC chromatography and stay updated on any
changes in safety protocols.
- Responsibility: I took responsibility for my work by ensuring accurate spotting, proper handling of TLC
plates, and reliable data recording. To enhance my practice, I can actively contribute to discussions on
optimizing experimental conditions and take the initiative to troubleshoot any issues that arise during
the chromatography process.
- Teacher feedback: My teacher Leo provided feedback on my performance, acknowledging my precise
spotting techniques and accurate Rf value calculations. This feedback motivates me to maintain my
attention to detail and precision.
- Areas for improvement: I need to further develop my skills in selecting and optimizing solvent systems
for better separation and identification of compounds on TLC plates. To address this, I could explore
,different solvent combinations, evaluate the impact of pH on separation, and consult with experts or
resources to gain insights into advanced TLC techniques.
2C: Paper chromatography of amino acids
P7: Summarise key personal competencies developed in relation to scientific skills undertaken:
Through the paper chromatography experiments involving amino acids, I developed the following key
personal competencies in relation to scientific skills:
- Sample preparation: I acquired skills in preparing samples containing amino acids and ensuring their
suitability for paper chromatography.
- Spotting techniques: I learned to spot the amino acid samples accurately on the chromatography paper,
ensuring clear and well-defined spots for separation.
- Separation and migration analysis: I gained experience in running paper chromatography and analysing
the migration of amino acids, allowing for the identification of different compounds present in the
samples.
- Visualization and interpretation: I developed the ability to visualize the separated amino acids and
interpret the results based on their migration distances and interactions with the chromatography paper.
M4: Analyse skills developed and suggest improvements to own practice.
- Working safely: I followed safety guidelines while handling solvents, amino acid samples, and
chromatography paper, including using protective equipment and ensuring proper waste disposal. To
improve my practice, I could actively seek safety information specific to amino acid chromatography and
stay updated on any changes in safety protocols.
- Responsibility: I took responsibility for my work by ensuring accurate spotting, proper handling of
chromatography materials, and careful data recording. To enhance my practice, I can actively engage in
discussions about optimizing experimental procedures and contribute to the development of protocols
that improve accuracy and reproducibility.
- Partner feedback: my classmate Mahak provided feedback on my performance, noting my precise
spotting techniques and careful observation of migration patterns. This feedback motivates me to
maintain my attention to detail and focus on improving my chromatography skills.
- Areas for improvement: I need to further develop my skills in optimizing chromatography conditions for
better separation and identification of amino acids. To address this, I could explore different solvent
systems, refine spotting techniques, and seek guidance from experts or resources to gain insights into
advanced chromatography methods.
,D4: Evaluate scientific skills developed in terms of potential for future progression.
Throughout the experiments involving colorimetry, titration, calorimetry, and chromatography in this
unit, several scientific skills have been developed that hold significant potential for future progression.
These skills include:
1. Laboratory techniques: The proficiency gained in laboratory techniques such as accurate
measurement, handling of chemicals, calibration of instruments, and adherence to safety protocols will
serve as a solid foundation for future scientific endeavours.
2. Data analysis and interpretation: The ability to collect, analyse, and interpret data from various
experiments is invaluable in scientific research and problem-solving. These skills can be applied across
different disciplines and experiments, enabling informed decision-making, and drawing reliable
conclusions.
3. Experimental design and optimization: Through the unit's experiments, we have learned to design
experiments, identify variables, optimize conditions, and troubleshoot issues. These skills will contribute
to the development of well-designed experiments in future scientific investigations.
4. Collaborative skills: The unit's experiments often involved working with partners or in teams. Effective
communication, collaboration, and the ability to give and receive feedback are essential skills that will
support future teamwork and project management in scientific environments.
5. Critical thinking and problem-solving: The challenges encountered during the unit's experiments
required students to think critically, analyse data, and apply scientific principles to overcome obstacles.
These problem-solving skills will be valuable in tackling complex scientific questions and designing
innovative solutions.
The skills developed in colorimetry, titration, calorimetry, and chromatography can be transferred and
applied to other units or scientific disciplines. For example:
- In biochemistry, the chromatography skills acquired can be applied to separate and analyse complex
mixtures of biomolecules.
- In chemistry, the analytical skills developed in colorimetry and spectroscopy can be used to quantify
pollutants or assess water quality.
- In chemistry, the knowledge gained from titration experiments can be applied to determine drug
concentrations and optimize dosages.
- In physics, the calorimetry skills acquired can be used to study phase transitions, reaction kinetics, and
heat transfer in various materials.
, Overall, the scientific skills developed in this unit provide a solid foundation for future progression and
open avenues for further exploration and specialization in diverse scientific fields.
D.D4: Evaluate scientific skills developed in terms of potential for future progression.
The scientific skills developed in these experiments hold enormous potential for future progression.
Some of the key skills include:
1. Laboratory Techniques: The experiments involved precise measurement techniques, proper handling
of chemicals, and adherence to safety protocols. These skills are essential for any laboratory-based work
and will be valuable in future scientific endeavours.
2. Analytical Skills: The experiments required data analysis, interpretation, and drawing conclusions.
These skills are crucial in scientific research and problem-solving, enabling researchers to make informed
decisions based on the data collected.
3. Experimental Design: Students learned to design experiments, identify variables, and optimize
conditions. These skills are vital for conducting well-controlled experiments and generating reliable
results in future scientific investigations.
4. Instrumentation Skills: The experiments involved the use of instruments like pH meters,
spectrophotometers, and calorimeters. Understanding how to operate and calibrate these instruments is
valuable in a wide range of scientific disciplines, allowing for accurate measurements and data collection.
5. Problem-Solving Abilities: The experiments presented challenges that required critical thinking and
problem-solving skills. Students had to troubleshoot issues, identify sources of error, and develop
strategies to overcome obstacles. These problem-solving abilities are transferable and valuable in various
scientific fields.
D.M4: Analyse skills developed and suggest improvements to own practice.
To further enhance their scientific skills, students can consider the following improvements to their
practice:
1. Working Safely: Continuously prioritize safety by following proper laboratory procedures, wearing
appropriate protective equipment, and being aware of potential hazards associated with the chemicals
and equipment used in the experiments. Stay updated on safety protocols and guidelines specific to
each experiment.
2. Precision and Accuracy: Focus on improving precision and accuracy in measurements, especially
during titrations and colorimetry. Develop techniques for consistent and reproducible results, such as
careful calibration of instruments and attention to detail when performing measurements.
