Carbon Dioxide Sublimation and Dissolution Equilibria

temperature T (°C)

25.5

moles of

CO

2

(n)

1

General

:4.10071×

-134

10

6.72632×

-267

10

is too small to represent as a normalized machine number; precision may be lost.

In this Demonstration, you can manipulate the number of moles of

CO

2

(

n

) and the temperature

T

(°C) to visualize both the equilibria of sublimation of solid

CO

2

and the dissolution of gaseous

CO

2

into aqueous solution. In the graphic, the left cylinder shows the sublimation of

CO

2

, beginning with solid

CO

2

. The equilibrium depends on the number of moles and the temperature. In the right cylinder, the dissolution of gaseous

CO

2

depends both on the Henry's law constant

k

H

(T)

and the ideal gas law (

PV=nRT

). On the right is a bar graph comparing the values of

Q

, the reaction quotient, and

K

, the equilibrium constant.

Q

will change as the molar concentration of carbon dioxide changes, while

K

will only change with temperature. The visual comparison of

Q

and

K

shows the direction of the reaction. If

Q

is smaller than

K

, the forward reaction is favored, while if

Q

is larger than

K

, the reverse reaction is favored.