Materials and Methods

1 

Materials

Equipment & Tools:

• Digital balance (±0.01 g precision)

• 25 mL graduated cylinder (for precise water measurement)

• 100 mL narrow-neck plastic bottle (to minimize headspace)

• Micro spatula (for transferring small solid quantities)

• Stirring rod (thin, 15 cm long)

• Thermometer (digital, ±0.1°C accuracy)

• Refrigerator (calibrated to 4±1°C)

• Timer (with 1-sec resolution)

2

Chemicals (Reduced Quantities)

• Citric acid (0.35 g ± 0.01 g)

• Sodium bicarbonate (0.46 g ± 0.01 g)

• Sucrose (5.00 g ± 0.05 g)

• Purified water (25.0 mL ± 0.5 mL)

• Food-grade flavoring (0.5 mL, if used)

3

Procedures

1. Balloon Preparation:

• Using dry funnel, pour 0.46g baking soda into balloon

• Stretch balloon neck over beaker mouth (don't let powder fall in yet)

• Ensure airtight seal between balloon and beaker rim

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2.  Solution Preparation:

• In separate container:

• Dissolve citric acid/sugar mix in 25mL water

• Stir until completely clear (~20 sec)

• Pour solution into prepared beaker

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3. Reaction Initiation:

• Lift balloon upright, allowing baking soda to descend into solution

• Immediately pinch balloon neck shut

• Gently swirl beaker 3 times (1 rotation/sec)

• Observe CO₂ production (balloon inflation)

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5. Data Collection:

• Start timer and scale when baking soda contacts solution

• Measure the mass of balloon and beaker(with the solution)

• Calculate CO₂ volume from balloon mass and amount of CO₂ loss/produced, also the mass of the solution before and after the reaction