Answer to Question #90056 in Organic Chemistry for Brandy

Question

the metabolism of glucose (molar mass 180.2 g/mol) with oxygen forms CO2 and H2O and releases 678 kcal/mol of energy. C6H12O6 (aq)+ 6 O2(g) <> 6 CO2(g) + 6H2O(l) glucose. how much energy is released when 21.0 g of glucose reacts (? Kcal)

Answer 1

First, the number of moles of glucose that is used in the reaction should be calculated:

n = m/M, where n - number of moles, m - mass, M - molar mass.

n (C₆H₁₂O₆) = 21 g / 180.2 g/mol = 0.12 mol.

Next, as 678 kcal is released from one mole of glucose, the metabolism of 0.12 mol of glucose results in the release of 0.12 mol × 678 kcal = 81.36 kcal of energy.

Answer: 81.36 kcal