# Non-Linear Solubility Trend

I am doing a lab on carbon dioxide solubility in water and I have a non-linear trend which seems to agree with the accepted trend. I am examining the change in solubility as a function of temperature. In the experiment I titrated carbonated water with sodium hydroxide and used molar ratios to determine the carbon dioxide content. The following graph shows the accepted trend:

I've been thinking but, can't seem to figure out why the trend is non-linear. Is there any intuition behind this trend?

• Nonlinear with respect to what? Amount of water? Amount of CO2? Temperature? Is it a closed system? Please be specific about what you are asking, as well as the experimental setup... – colnegn Mar 6 '16 at 23:59
• Sorry, it is updated now. – Yulmart Mar 7 '16 at 0:01

$lnK_2 - lnK_1 = \frac{\Delta H }{R} (\frac{1}{T_1}-\frac{1}{T_2})$ . Thus, the graph is not linear.