Part 2a: Degassing Calculations

The idea here is to determine the mass of CO₂ you released into the atmosphere during the first part of your experiment. Watch your unit conversions!

First, a few assumptions:

• We shall assume that the physical properties of Diet Coke are the same as those of water (H₂O) at room temperature (20˚C)
• We shall assume that a typical soda contains ~0.5% CO₂ by weight prior to being opened (in reality this may vary by quite a bit)

We start by determining the total mass of CO₂ present at the beginning of the experiment (prior to opening the bottle). In order to do this, first you will need to determine the mass of Diet Coke. Use the graph below to determine the density of water at 20˚C; we will assume your Diet Coke has the same density. Note that 1 cm³ = 1 mL.

Water Density as a Function of Temperature

Credit: www.chem1.com

1. Approximately how many grams of Diet Coke (water) are in a 2 liter bottle?
2. Given that the concentration of CO₂ in soda is ~0.5% by weight, how many grams of CO₂ are in the bottle?

Solubility is the amount of a compound that will remain in solution under a given set of conditions. Use the graph below to estimate the solubility of CO₂ in water at 20˚C and atmospheric pressure.

Solubility of CO₂ in Water as a Function of Temperature

Credit: The Engineering ToolBox

The amount of CO₂ released is given by the total amount present prior to opening the bottle minus the amount retained after the degassing experiment.

1. How many grams of CO₂ will remain dissolved in our 2 liters of Diet Coke after the experiment is done?
2. What was the mass of CO₂ released?