In the process of respiration, glucose is oxidized completely. In fermentation, O2 is absent, and glucose is broken down into Co2 and H2o.
Calculate delta g for respiration of 1.00 g of glucose
Calculate delta g for fermentation of 1.00 g of glucose.
My answers:
-16.0 kJ and -1.26 kJ
what I need help with is:
Calculate delta g for oxidation of the ethanol from part C.
answer in kJ/g..............thanks!
To calculate the ΔG (change in Gibbs free energy) for the oxidation of ethanol, we need to use the equation:
ΔG = ΔGf° + RTlnQ
Where:
- ΔGf° is the standard Gibbs free energy change for the reaction
- R is the gas constant (8.314 J/mol·K or 0.008314 kJ/mol·K)
- T is the temperature in Kelvin
- lnQ is the natural logarithm of the reaction quotient
In this case, we need to consider the oxidation of ethanol. The balanced equation for the oxidation of ethanol to acetic acid is:
C2H5OH + 2O2 → 2CH3COOH + 2H2O
The ΔGf° values are:
- ΔGf° (C2H5OH) = -278.0 kJ/mol
- ΔGf° (CH3COOH) = -486.5 kJ/mol
Now, we can calculate the ΔG for the reaction:
ΔG = (2ΔGf° (CH3COOH) + 2ΔGf° (H2O)) - (ΔGf° (C2H5OH) + 2ΔGf° (O2))
Let's assume the temperature is 298 K.
ΔG = (2*(-486.5) + 2*0) - (-278.0 + 2*0)
ΔG = (-973.0) - (-278.0)
ΔG = -695.0 kJ/mol
To get the answer in kJ/g, we need to convert the ΔG from kJ/mol to kJ/g.
Since the molar mass of ethanol (C2H5OH) is approximately 46.07 g/mol, we can divide the ΔG by the molar mass to find the ΔG in kJ/g.
ΔG = -695.0 kJ/mol / 46.07 g/mol
ΔG = -15.1 kJ/g (approximately)
Therefore, the ΔG for the oxidation of ethanol is approximately -15.1 kJ/g.