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### 5.61a

Posted: Sat Jan 18, 2020 10:27 pm
5.61 The overall photosynthesis reaction is 6 CO2(g) + 6 H2O(l) -- C6H12O6(aq) + 6 O2(g), and H = 12802 kJ. Suppose that the reaction is at equilibrium. State the effect that each of the following changes will have on the equilibrium composition: tends to shift toward the formation of reactants, tends to shift toward the formation of products, or has no effect. (a) The partial pressure of O2 is increased.

The solutions manual states that because more O2 is added, the reaction will shift towards products. Does increasing the partial pressure of O2 mean that they are adding more O2 gas particles? I initially thought there would be no change since the moles of gaseous particles are equal on both sides.

### Re: 5.61a

Posted: Sat Jan 18, 2020 10:39 pm
I believe that increasing the partial pressure of O2 is achieved by means of adding more O2 gas particles. And remember that P (partial pressure) = concentration * R * T (temperature).

### Re: 5.61a

Posted: Sun Jan 19, 2020 2:14 pm
Shutong Hou_1F wrote:I believe that increasing the partial pressure of O2 is achieved by means of adding more O2 gas particles. And remember that P (partial pressure) = concentration * R * T (temperature).

Doesn't increasing the partial pressure have the same effect as increasing the concentration? Why doesn't the equilibrium shift to the left?

### Re: 5.61a

Posted: Tue Jan 21, 2020 11:57 pm
Gabriella Bates 2L wrote:5.61 The overall photosynthesis reaction is 6 CO2(g) + 6 H2O(l) -- C6H12O6(aq) + 6 O2(g), and H = 12802 kJ. Suppose that the reaction is at equilibrium. State the effect that each of the following changes will have on the equilibrium composition: tends to shift toward the formation of reactants, tends to shift toward the formation of products, or has no effect. (a) The partial pressure of O2 is increased.

The solutions manual states that because more O2 is added, the reaction will shift towards products. Does increasing the partial pressure of O2 mean that they are adding more O2 gas particles? I initially thought there would be no change since the moles of gaseous particles are equal on both sides.

Hi! I checked the answer key and it says that equilibrium shifts towards the reactants side of the equation. This makes more sense because increasing partial pressure has the same effect as increasing the concentration. If there is an increase in products, the reaction will use it up by creating more reactants, hence why the reaction shifts to the left.