Hydrofluoric acid etches glass by reacting with the silica in it according to the following equation.
H° = 54.5 kJ and S° = 436.5 J/K Calculate G° at 25°C for this reaction.
so because i can not post links on here, just take out the spaces in here
ht tp://qcommons. org/content/ hydrofluoric -acid-etches-glass-reacting-th-0
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To calculate the standard Gibbs free energy change (ΔG°) at 25°C for a reaction, you can use the equation:
ΔG° = ΔH° - TΔS°
where ΔH° is the standard enthalpy change, ΔS° is the standard entropy change, and T is the temperature in Kelvin.
Given parameters:
ΔH° = 54.5 kJ
ΔS° = 436.5 J/K
T = 25°C = 25 + 273.15 = 298.15 K
First, convert ΔH° to J:
ΔH° = 54.5 kJ * 1000 J/kJ = 54,500 J
Now, substitute the values into the equation to calculate ΔG°:
ΔG° = ΔH° - TΔS°
ΔG° = 54,500 J - (298.15 K * 436.5 J/K)
ΔG° = 54,500 J - 129,997.68 J
Calculating the result:
ΔG° = -75,497.68 J
So, the standard Gibbs free energy change at 25°C for this reaction is approximately -75,497.68 J.