Consider the following reaction at 298 K. C ( graphite ) + 2 H 2 ( g ) ⟶ CH 4 ( g ) Δ H ∘ = − 74.6 kJ and Δ S ∘ = − 80.8 J / K Calculate the following quantities. Δ S sys = J/K Δ S surr = J/K Δ S univ = J/K Is this reaction spontaneous? yes no

Answer :

Entropy of system = -80.8 J/K

Entropy of surrounding = 253.7 J/K

Entropy of universe = 172.9 J/K

The reaction is spontaneous.

The process is a spontaneous process.

Explanation :

The given chemical reaction is:

Entropy of reaction = = Entropy of system = -80.8 J/K

Now we have to calculate the entropy of surrounding.

Entropy of surrounding  =

Entropy of surrounding  =

Entropy of surrounding  =

Entropy of surrounding  = 253.7 J/K

As, we know that:

Entropy of universe = Entropy of system + Entropy of surrounding

Entropy of universe = -80.8 J/K + (253.7 J/K)

Entropy of universe = 172.9 J/K

Now we have to calculate the Gibbs free energy.

As we know that,

where,

= standard Gibbs free energy  = ?

= standard enthalpy = -74600 J

= standard entropy = -80.8 J/K

T = temperature of reaction = 298 K

Now put all the given values in the above formula, we get:

For the reaction to be spontaneous, the Gibbs free energy of the reaction is negative or we can say that the value of

As the value of is less than zero that means the reaction is spontaneous.

it's filtration, but this is an assumption so my apologies if i got this