Chapter 4, Problem 4.16NP

The total surface area of Asia consisting of forest, cultivated land, grass land, and desert is $\text{4}.\text{46}\times \text{1}{0}^{\text{7}}{\text{km}}^{\text{2}}$. Every year, the mass of carbon fixed by photosynthesis by vegetation covering this land surface according to the reaction ${\text{CO}}_{\text{2}}\left(\text{g}\right)+{\text{6 H}}_{\text{2}}\text{O}\left(\text{l}\right)\to {\text{C}}_{\text{6}}{\text{H}}_{\text{12}}{\text{O}}_{\text{6}}\left(\text{s}\right)+{\text{6O}}_{\text{2}}\left(g\right)$ is about $\text{455}.\times \text{1}{0}^{\text{3}}\text{kg}{\text{km}}^{-2}$. Calculate the annual enthalpy change resulting from photosynthetic carbon fixation over the land surface given earlier. Assume $\text{P}=\text{1 bar}$ and $\text{T}=\text{298 K}$.