In: Chemistry
Consider the formation of glucose from carbon dioxide and water
(i.e., the reaction of the photosynthetic process):
6CO2(g)+6H2O(l)→C6H12O6(s)+6O2(g).
The following table of information will be useful in working this
problem:
T= 298 K | CO2(g) | H2O(l) | C6H12O6(s) | O2(g) |
ΔH∘f (kJ mol−1) | -393.5 | -285.8 | -1273.1 | 0.0 |
S∘ (J mol−1 K−1) | 213.8 | 70.0 | 209.2 | 205.2 |
C∘P,m (J mol−1 K−1) | 37.1 | 75.3 | 219.2 | 29.4 |
A. Calculate the entropy change for this chemical system at T = 298 K.
B. Calculate the enthalpy change for this chemical system at T = 298 K.
C. Calculate the entropy change of the surroundings at T = 298 K..
D. Calculate the entropy change of the universe at T = 298 K.
E. Calculate the entropy change for this chemical system at 320. K .
F. Calculate the enthalpy change for this chemical system at 320. K .
G. Calculate the entropy change of the surroundings at 320. K .
H. Calculate the entropy change of the universe at 320. K .
Thank you so much
A) The entropy change for this chemical system at T = 298 K:
dS = Sproducts - Sreactants
6CO2(g) + 6H2O(l)→ C6H12O6(s) + 6O2(g).
dS = (C6H12O6 + 6*O2) - (6*CO2 + 6*H2O)
dS = (209.2 + 6*205.5) - (6*213.8 + 6*70)
dS = -260.6 J/ mol k
B)
The enthalpy change for this chemical system at T = 298 K.
Enthalpy change:
dH = Hproudcts - Hreactants
dH = (C6H12O6 + 6*O2) - (6*CO2 + 6*H2O)
dH = (-1273.1 + 6 * 0 ) - (6 * -393.5 + 6 * -285.8)
dH = 2802.7 J/mol k
C)
The entropy change of the surroundings at T = 298 K.
Entropy change in surroundings:
The temperature of surroundings does not change, so assume T = isothermal, 298 K
So,
Qsurrounding = - HRxn
Ssurroundings = Qsurr/T
dSsurrounginds = -HRxn / T = -2802.7 / (298)
dSsurroundings = -9.4050 J/mol k
D)
The entropy change of the Universe at T = 298K
Entropy of the universe:
dSsuniverse = dSsurroundings + +dSsystem
= -260.6 J/mol k - 9.4050 J/mol k
= -270.005 J/molK