For the reaction in the plant cells:6CO2 (g) + 12 H2O (λ) → C6H12O6 (s) + 6O2 (g) + 6H2O (λ); rGº = 3000 kJ/mol ATP → ADP+ PO43− ; ∆rGº = -30 kJ/mol Glucose is stored in the plant cell as starch, (C6H10O5)n. To produce 162 gm of starch how many minimum moles of ATP are required?
Correct answer: A. 100 mol
- A. 100 mol
- B. 10 mol
- C. 20 mol
- D. 200 mol
Explanation
The formation of glucose from CO2 and H2O in plant cells is a non-spontaneous process with a Gibbs free energy change of 3000 kJ/mol, requiring an energy source to proceed. ATP hydrolysis, with a Gibbs free energy change of -30 kJ/mol, provides the necessary energy. To produce 162 grams of starch, equivalent to 1 mole of glucose (molar mass = 162 g/mol), 3000 kJ of energy is needed. Dividing the energy required by the energy provided per mole of ATP (30 kJ/mol) results in the need for 100 moles of ATP. Thus, Option A is correct. Options B and C are incorrect because they underestimate the energy required, while Option D overestimates it.
Last updated
About Thermochemistry and Energetics of Chemical Reactions
Thermochemistry measures energy changes in chemical reactions and distinguishes exothermic from endothermic processes. Work covers systems, surroundings and state functions, internal energy, the first law of thermodynamics, enthalpy and Hess's law, including the sign conventions used when heat enters or leaves a system.
Practise Thermochemistry and Energetics of Chemical Reactions
728 free Thermochemistry and Energetics of Chemical Reactions MCQs from Chemistry, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Chemistry questions like this
Chemistry is on 12 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
1/2 H2(g) ➞ H(g) ∆H = 218 kJ mol-1.In this reaction, ∆H will be called:
1 Kcal is equal to:
2P(s) 3CI2(g) 2PCI3 ∆H= 151.8 kJ PCl3+ CI2(g) , PCI5(g); ∆H = -32.8 kJFrom the following data, the heat of formation of PCI5 comes out to be :
5 calories are equivalent to _ Joule.
5 mole of an ideal gas expand reversibly from a volume of 8 dm3 to 80 dm3 at a temperature of 27°C. Calculate the change in entropy.