Question

the standard free energy change for a chemical reaction is 13.3 kj/mol. what is the equilibrium constant for the reaction at 125 °c? (r = 8.314 j/k⋅mol)

Answer 1

The equilibrium constant (K) for a reaction with a standard free energy change (ΔG°) of 13.3 kJ/mol at 125 °C can be calculated using the formula ΔG° = -RT ln(K). After necessary conversions and rearrangements, K is found to be approximately 0.018.

Step-by-step explanation:

The student has asked about calculating the equilibrium constant for a reaction when its standard free energy change (ΔG°) is given. For a chemical reaction with a ΔG° of 13.3 kJ/mol at 125 °C, the equilibrium constant (K) can be calculated using the following thermodynamic equation:

ΔG° = -RT ln(K)

Where R is the universal gas constant (8.314 J/K·mol), T is the temperature (in kelvin), and K is the equilibrium constant. Converting the temperature to kelvin (398.15 K) and plugging in the values, the calculation becomes:

13.3 kJ/mol * 1000 J/kJ = -8.314 J/K·mol * 398.15 K * ln(K)

To solve for K, we rearrange the equation to:

ln(K) = - (13.3 kJ/mol * 1000 J/kJ) / (8.314 J/K·mol * 398.15 K)

ln(K) = - (13300 J/mol) / (3307.507 J/K·mol)

ln(K) = -4.0208

Taking the exponent of both sides to solve for K, we get:

K =
`e^(-4.0208)`≈ 0.018

Therefore, the equilibrium constant for the reaction at 125 °C is approximately 0.018.

Answer 2

The equilibrium constant can be calculated using the formula K = e^-(ΔG°/RT). By substituting the given values into the equation, we can find the equilibrium constant for the reaction at 125 °C.

Step-by-step explanation:

The equilibrium constant for a chemical reaction can be calculated using the formula:

K = e-(ΔG°/RT)

Given that the standard free energy change (ΔG°) is 13.3 kJ/mol and the temperature (T) is 125 °C (converted to Kelvin: 125 + 273 = 398 K), we can substitute these values into the equation:

K = e-(13.3/(8.314 * 398))

Calculating this expression will give us the equilibrium constant for the reaction at 125 °C.