Limitations

Sugar concentrations were tested one at a time rather than simultaneously
→ Limitation: Environmental conditions (like room temperature) could change between tests, affecting results.
→ Fix: Test all sugar concentrations at the same time using identical setups.

Timing between adding sugar and starting the timer may not have been consistent
→ Limitation: Delays could let fermentation start before the timer, giving inaccurate results.
→ Fix: Have a second person start the timer the instant sugar is added and the balloon is placed.

Water temperature was only adjusted approximately (to ~30°C)
→ Limitation: Slight temperature differences affect yeast fermentation.
→ Fix: Use a thermometer to measure precisely and use a water bath or incubator to maintain a stable temperature.

Stirring may have varied in speed or force
→ Limitation: Uneven mixing could result in different sugar availability.
→ Fix: Use a mechanical stirrer to standardise stirring.

Measuring balloon circumference with tape and a ruler introduces human error
→ Limitation: The tape might not be placed at the widest point consistently, leading to inaccurate readings.
→ Fix: Use a flexible seamstress tape measure and mark a specific point on each balloon for measurement.

Differences in balloon elasticity could affect inflation
→ Limitation: Balloons may stretch differently even if the gas volume is the same.
→ Fix: Pre-stretch balloons or use syringes or gas syringes to measure gas volume directly.

Risk of small air leaks where the balloon was fitted
→ Limitation: Escaping gas would make the balloon seem less inflated.
→ Fix: Secure the balloon with a rubber band or clamp to ensure an airtight seal.

Actual amount of yeast could vary if some stuck in the funnel
→ Limitation: Unequal yeast amounts could cause uneven fermentation rates.
→ Fix: Add yeast directly to the flask or rinse the funnel with water into the flask to ensure all yeast enters.

Washing and drying flasks between trials could leave residue or moisture
→ Limitation: Leftover residue or moisture could alter the concentration of the mixture.
→ Fix: Rinse thoroughly with distilled water and allow flasks to dry completely, or use separate flasks for each trial.

The 15-minute duration may have been too short for lower sugar concentrations
→ Limitation: The yeast may not have produced measurable gas, making results hard to compare.
→ Fix: Extend the fermentation time (e.g., 30 minutes or longer) or measure gas production over multiple time points.