OCR A Jun 2013 Paper 5 Q6

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The equation for the reaction of CO2 and H2O to produce glucose, C6H12O6, and O2 is shown below. 6CO2(g) + 6H2O(l) C6H12O6(s) + 6O2(g) H = +2879 kJ mol1; S = 256 J K1 mol1 14 Standard entropies are given in the table below. Substance S o / J K1 mol1 CO2(g) 214 H2O(l) 70 O2(g) 205 (a) (i) Calculate the standard entropy of glucose. (ii) Calculate G, in kJ mol1, at 25 C. Show all your working. S o =J K1 mol1 [2] (iii) Explain why this reaction is not feasible at any temperature. G =kJ mol1 [2][1]OCR 2013<br />
 15 (b) Although the reaction between CO2 and H2O to form C6H12O6 and O2 appears not to be feasible, plants are able to make the reaction take place spontaneously by photosynthesis. Each year, 3.41018 kJ of solar energy is taken in by all the plants on the Earth to make photosynthesis take place. Calculate the mass of carbon dioxide that is removed each year from the atmosphere by photosynthesis on Earth. mass of CO2 =[2] [Total: 7]OCR 2013 Turn over<br />

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