Reaction #5 - How to make carbonic acid

Carbonic acid is a weak acid, but if you want to make it, here's how:

Materials:

• Vinegar / calcium chloride powder (vinegar - please follow normal steps and "A" steps, calcium chloride - please follow normal steps and "B" steps)
• Sodium bicarbonate
• Water
• 25ml graduating cylinder
• 1000ml (1 litre) beaker
• Conical flask with hole at the side that connects to a glass pipette
• Stopper

Step 1: Place the 25ml graduating cylinder into the 1000ml beaker.

Step 2: Pour the sodium bicarbonate into the conical flask.

Step 3: Pour water into the graduating cylinder.

Step 4: Put the glass pipette into the graduating cylinder.

Step 5A: Pour the vinegar (a bit will do) into the conical flask and stopper it off.

Step 5B: Add the calcium chloride into the conical flask and then add 10 ml of water (stopper it off immediately).

Step 6: Wait till no more gas bubbles come out of the pipette.

Step 7: Obtain the product (it's in the graduating cylinder)

Here're the chemical equations of this process:

For A:

Sodium bicarbonate + Vinegar (Acetic / ethanoic acid) → Sodium acetate / ethanoate + Water + Carbon dioxide

NaHCO₃ + CH₃COOH → CH₃COONa + H₂O + CO₂

For B:

Sodium bicarbonate + Calcium chloride → Sodium chloride + Calcium carbonate + Water + Carbon dioxide

2NaHCO₃ + CaCl₂ → 2NaCl + CaCO₃ + H₂O + CO₂

(This actually goes in a multi-step process but I'm just simplifying it here.)

In both steps, the carbon dioxide dissolves into the water in the graduating cylinder to form carbonic acid:

Carbon dioxide + Water → Carbonic acid

CO₂ + H₂O → H₂CO₃

Improvements: Add crushed ice and water to the beaker containing the graduating cylinder (increases yield because gases dissolve better in colder water).

 

Good luck! 加油！

Reaction by GITS