Consider the decomposition of a metal oxide to its elements, where M represents a generic metal.
M203(s)---> 2M(s) + 3/2 O2(g) info given for Gf(kJ/mol): M203= -10.60 M(s)=0 O2(g)= 0 1.) what is the standard change in Gibbs energy for rxn as written in forward direction? (kJ/mol)
2.) What is the equilibrium constant (K) of this rxn, as written in forward direction at 298K?
3.) What is the equilibrium pressure of O2(g) over M(s) at 298K? (atm)
For 1.) I got 10.6 kJ/mol and this is correct For 2.) I got K= -4.28 and it marked me wrong. Now I got an answer of .01387. Is this correct???
For 3.) I got PO2= 0.0016 atm and it marked me wrongI don't know how it is wrong.
Could you please check #2 and #3 and tell me what I did wrong and what are the answers thanks.

For 1: The standard Gibbs free energy change of the reaction is 10.60 kJ/mol

For 2: The equilibrium constant for the given reaction at 298 K is

For 3: The equilibrium pressure of oxygen gas is 0.0577 atm

Explanation:

The equation used to calculate standard Gibbs free energy change of a reaction is:

For the given chemical reaction:

The equation for the standard Gibbs free energy change of the above reaction is:

We are given:

Putting values in above equation, we get:

Hence, the standard Gibbs free energy change of the reaction is 10.60 kJ/mol

Relation between standard Gibbs free energy and equilibrium constant follows:

where,

= Standard Gibbs free energy = 10.60 kJ/mol = 10600 J/mol    (Conversion factor: 1 kJ = 1000 J )

R = Gas constant = 8.314 J/K mol

T = temperature = 298 K

= equilibrium constant = ?

Putting values in above equation, we get:

Hence, the equilibrium constant for the given reaction at 298 K is

The expression of for above equation follows:

The concentration of pure solids and pure liquids are taken as 1 in the expression. That is why, the concentration of metal and metal oxide is taken as 1 in the expression.

Putting values in above expression, we get:

Hence, the equilibrium pressure of oxygen gas is 0.0577 atm

the answer is definitely c.

colorless gas, exhibiting a blue glow when placed in an electric field

b) solid

its a type of rock