Calculate the equilibrium constant for the reaction

NiO(s) + H2(g) → Ni(s) + H2O(g)

at 1023K from the following data:
Ni(s) + ½ O2(g) → NiO(s) ΔG0 = -244,555 + 98.53 T [J]
H2(g) + ½ O2(g) → H2O(g) ΔG0 = -246,438 + 54.81 T [J]

Could a pure nickel sheet be annealed at 1023K in an atmosphere containing 95% H2O and 5% H2 by volume without oxidation?

To calculate the equilibrium constant (K) for the given reaction, we can use the relationship between the standard Gibbs free energy change (ΔG°) and K:

ΔG° = -RT ln(K)

where:
R is the gas constant (8.314 J/mol·K)
T is the temperature in Kelvin

First, let's calculate ΔG° for the reaction Ni(s) + ½ O₂(g) → NiO(s) at 1023 K using the given data:
ΔG°(1) = -244,555 + 98.53 × 1023 = -144,518.385 J/mol

Next, the ΔG° for the reaction H₂(g) + ½ O₂(g) → H₂O(g) at 1023 K:
ΔG°(2) = -246,438 + 54.81 × 1023 = -191,136.37 J/mol

Now, we can calculate ΔG° for the desired reaction:
ΔG°(reaction) = ΔG°(1) +ΔG°(2)

Since the reaction equation is:
NiO(s) + H₂(g) → Ni(s) + H₂O(g)

The stoichiometric coefficient for NiO(s) and Ni(s) is 1. The stoichiometric coefficient for H₂O(g) and H₂(g) is also 1.

Thus, ΔG°(reaction) = ΔG°(1) + ΔG°(2) = -144,518.385 + (-191,136.37) = -335,654.755 J/mol

Now, we can substitute the value of ΔG°(reaction) into the equation:
ΔG° = -RT ln(K)

-335,654.755 J/mol = -(8.314 J/mol·K) × (1023 K) × ln(K)

To solve for K, we rearrange the equation:

ln(K) = -335,654.755 / [(8.314 J/mol·K) × (1023 K)]
ln(K) = -41.13796

Taking the exponential of both sides:

K = e^(-41.13796)

Using a calculator, K ≈ 1.341 × 10^(-18)

Now, let's analyze the second part of your question:

Could a pure nickel sheet be annealed at 1023K in an atmosphere containing 95% H2O and 5% H2 by volume without oxidation?

To determine if the pure nickel sheet will oxidize, we consider the partial pressures of H₂O and H₂ in the atmosphere.

Assuming ideal gas behavior, the partial pressure of H₂O is 95% of the total pressure, and the partial pressure of H₂ is 5% of the total pressure.

Given that the total pressure is not mentioned, we cannot determine if pure nickel will oxidize or not, as the pressure affects the equilibrium position.

To determine this accurately, we would need to know the total pressure of the atmosphere in which annealing occurs.