LeChâtelier’s Principle and the Solubility of Carbon Dioxide


This activity demonstrates the effect of pressure and temperature on three reversible reactions: the solubility of carbon dioxide in water, the reaction of dissolved carbon dioxide and water to form H2CO3, and the weak acid ionization of H2CO3 to give HCO3- and H+ ions. For simplicity sake in terms of classroom discussion, these reactions are combined into one equation in Equation 1. The position of equilibrium for this reaction can be determined by measuring the concentration of H+ ions in solution. Seltzer water is used as a source of dissolved carbon dioxide, and the concentration of H+ ions is estimated using
bromcresol green as an indicator. The indicator is yellow when the pH is less than 3.8, blue when the pH is greater than 5.2, and various shades of green in the pH range 3.8–5.2. A sealed syringe is used to provide a closed system.

2CO2(g) + H2O(l) → CO2(aq) + H+(aq) + HCO3 –(aq) Equation 1

Click here to download the complete activity from Flinn 

Website:  https://www.flinnsci.ca/

Facebook: https://www.facebook.com/flinnscientificcanada

 

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

w

Connecting to %s