Question

Calculate the energy required to convert 2.50L of carbon dioxide at SLC to glucose according to the equation :
6CO2(g) + 6H2O(l) -> C6H12O6(aq) + 6O2(g) Δ H = +2803kJ/mol
the answer is 47.7kj but I can't figure out how to get it.

Answer 1

Okay, in this reaction, 2803 kJ of energy is required to form 1 mol glucose. 6 mol CO2 are required to form 1 mol glucose. At SLC, there are 24.5 L of gas in 1 mole.

So at SLC, 2.50 L of CO2 would be 2.50 L / 24.5 mol/L = 0.102 mol CO2. To get the moles of glucose produced from that, we divide that by 6, since 1 mol glucose is formed per 6 mol CO2. 0.102 mol CO2 / 6 mol glucose/mol CO2 = 0.0170 mol glucose. Forming 1 mol glucose requires 2803 kJ, so forming 0.0170 mol requires 0.0170 mol x 2803 kJ/mol = 47.7 kJ.

Answer 2

Thanks