CO₂ y Prueba con Agua de Cal

Detección de dióxido de carbono con hidróxido de calcio

Gas Laws Beginner (Middle School) 20 min ~$5,00

Objetivo

Generar gas dióxido de carbono a partir de una reacción carbonato-ácido y confirmar su identidad usando la prueba del agua de cal.

Antecedentes

When baking soda (sodium bicarbonate) reacts with vinegar (acetic acid), CO₂ gas is produced. Bubbling this gas through limewater (calcium hydroxide solution) produces a characteristic white milky precipitate of calcium carbonate, confirming the presence of CO₂.

Advertencias de seguridad

  • Limewater is mildly irritating — avoid eye contact
  • CO₂ is an asphyxiant in large quantities — work in ventilated area

EPP requerido

goggles

Materiales

  • Baking soda (NaHCO₃) (10 g)
  • White vinegar (50 mL)
    5% acetic acid
  • Limewater (Ca(OH)₂ solution) (100 mL)
    Clear, saturated

Equipamiento

Erlenmeyer flask (250 mL) Rubber stopper with delivery tube Test tubes Rubber tubing

Procedimiento

1

Pour 100 mL of clear limewater into a test tube or small beaker.

2 min
2

Place 10 g of baking soda in the Erlenmeyer flask.

1 min
3

Add 50 mL of vinegar to the flask. Quickly insert the stopper with delivery tube.

2 min Vigorous effervescence
4

Direct the delivery tube into the limewater. Bubble the CO₂ through for 2-3 minutes.

3 min
5

Observe the limewater turning milky white as calcium carbonate precipitate forms.

2 min
6

Continue bubbling. If enough CO₂ passes through, the solution may turn clear again as soluble Ca(HCO₃)₂ forms.

5 min

Resultados esperados

The clear limewater turns milky white due to CaCO₃ precipitation: Ca(OH)₂ + CO₂ → CaCO₃ + H₂O. With excess CO₂, the milkiness clears: CaCO₃ + CO₂ + H₂O → Ca(HCO₃)₂.

Limpieza

Neutralize remaining vinegar solution. Dispose of limewater down the drain. Rinse all equipment.

Frequently Asked Questions

What is the objective of CO₂ y Prueba con Agua de Cal?
Generar gas dióxido de carbono a partir de una reacción carbonato-ácido y confirmar su identidad usando la prueba del agua de cal.
How difficult is CO₂ y Prueba con Agua de Cal?
This experiment is rated as Beginner (Middle School). It takes approximately 20 minutes to complete.
What safety precautions are needed for CO₂ y Prueba con Agua de Cal?
Key safety precautions include: Limewater is mildly irritating — avoid eye contact; CO₂ is an asphyxiant in large quantities — work in ventilated area.
What materials are needed for CO₂ y Prueba con Agua de Cal?
The main materials required are: Baking soda (NaHCO₃), White vinegar, Limewater (Ca(OH)₂ solution).
What results should I expect from CO₂ y Prueba con Agua de Cal?
The clear limewater turns milky white due to CaCO₃ precipitation: Ca(OH)₂ + CO₂ → CaCO₃ + H₂O. With excess CO₂, the milkiness clears: CaCO₃ + CO₂ + H₂O → Ca(HCO₃)₂.