The spontaneity of a reaction can be determined using the Gibbs free energy equation:

ΔG = ΔH - TΔS

where:
ΔG is the change in Gibbs free energy,
ΔH is the change in enthalpy,
T is the absolute temperature in Kelvin,
ΔS is the change in entropy.

The reaction is spontaneous if ΔG is negative.

Let's calculate ΔG for both temperatures:

1. At 500 K:
ΔG = 62.4 kJ/mol - 500 K * 0.145 kJ/(mol·K) = 62.4 kJ/mol - 72.5 kJ/mol = -10.1 kJ/mol

Since ΔG is negative, the reaction is spontaneous at 500 K.

2. At 298 K:
ΔG = 62.4 kJ/mol - 298 K * 0.145 kJ/(mol·K) = 62.4 kJ/mol - 43.21 kJ/mol = 19.19 kJ/mol

Since ΔG is positive, the reaction is not spontaneous at 298 K.

So, the correct answer is A. It is spontaneous at 500 K.

Question

The spontaneity of a reaction can be determined using the Gibbs free energy equation:

ΔG = ΔH - TΔS

where:
ΔG is the change in Gibbs free energy,
ΔH is the change in enthalpy,
T is the absolute temperature in Kelvin,
ΔS is the change in entropy.

The reaction is spontaneous if ΔG is negative.

Let's calculate ΔG for both temperatures:

1. At 500 K:
ΔG = 62.4 kJ/mol - 500 K * 0.145 kJ/(mol·K) = 62.4 kJ/mol - 72.5 kJ/mol = -10.1 kJ/mol

Since ΔG is negative, the reaction is spontaneous at 500 K.

2. At 298 K:
ΔG = 62.4 kJ/mol - 298 K * 0.145 kJ/(mol·K) = 62.4 kJ/mol - 43.21 kJ/mol = 19.19 kJ/mol

Since ΔG is positive, the reaction is not spontaneous at 298 K.

So, the correct answer is A. It is spontaneous at 500 K.

Knowee AI · Accepted Answer