Question

Given the three equations below, what is the heat of reaction for the production of glucose, C6H12O6, as described by this equation?

6C(s)+6H₂(g)+3O₂(g)→C₆H₁₂O₆(s)
C(s)+O₂(g)→CO₂(g),∆H=–393.51kJ
​ O₂(g)→H₂O(l),∆H=–285.83kJ
C₆H₁₂O₆(s)+6O₂(g)→6CO₂(g)+H₂O(l),∆H=–2803.02kJ

a) –1273.02 kJ
b) –3482.36 kJ
c) –1730.17 kJ
d) –2123.68 kJ

Answer 1

The heat of reaction for the production of glucose is -1273.0 kJ.

Step-by-step explanation:

The heat of reaction for the production of glucose (C6H12O6) can be calculated by using the concept of Hess's law. We can write two equations that can be added together to give the desired equation and for which the enthalpy changes are known:

2CO(g) → 2C(s) + O₂(g), ∆H = +221.0 kJ

C(s) + O₂(g) → CO₂(g), ∆H = -393.5 kJ

Addind these two equations together gives:

2CO(g) + C(s) + 6O₂(g) → 2C(s) + 6CO₂(g), ∆H = -1272.9 kJ

The heat of reaction for the production of glucose is therefore -1273.0 kJ.