In the chemical equation for photosynthesis, carbon dioxide and water are converted to glucose and oxygen. 6CO_2 + 6H_2O -> C_6H_12O_6 + 6O_2. What component could be added to complete this chemical equation?

May 16, 2018

You should incorporate an energy term....

Explanation:

We KNOW that we burn carbohydrates, sugars, as a source of chemical energy...this is what happens to the sugar we put on our cornflakes this morning. The energy has to come from somewhere...and the source is sunlight...the photosynthesis is driven by sunlight..

So we could write...

$6 C {O}_{2} \left(g\right) + 6 {H}_{2} O \left(g\right) \stackrel{h \nu}{\rightarrow} {C}_{6} {H}_{12} {O}_{6} \left(a q\right) + 6 {O}_{2} \left(g\right)$

...or...perhaps more appropriately...

$6 C {O}_{2} \left(g\right) + 6 {H}_{2} O \left(g\right) + \Delta \rightarrow {C}_{6} {H}_{12} {O}_{6} \left(a q\right) + 6 {O}_{2} \left(g\right)$

..that is we include an energy term....

The reverse reaction, respiration, releases this energy...

${C}_{6} {H}_{12} {O}_{6} \left(s\right) + 6 {O}_{2} \left(g\right) \rightarrow 6 C {O}_{2} \left(g\right) + 6 {H}_{2} O \left(g\right) + \Delta$