The** total entropy or the entropy of the universe** is also related to the can be calculated using the entropy of the system (reaction) and entropy of the surroundings:

$\overline{){\mathbf{\u2206}}{{\mathbf{S}}}_{{\mathbf{univ}}}{\mathbf{=}}{\mathbf{\u2206}}{{\mathbf{S}}}_{{\mathbf{system}}}{\mathbf{+}}{\mathbf{\u2206}}{{\mathbf{S}}}_{{\mathbf{surroundings}}}}$

**Step 1: **Calculate ΔS°_{system}.

**ΔS° _{sys} = ΔS°_{rxn}**

**ΔS° C _{graphite} = 5.686 J/(mol•K)**

**ΔS° H _{2} = 130.6 J/(mol•K)**

**ΔS° CH _{4} = 186.1 J/(mol•K)**

Consider the following reaction at 298 K:

C(graphite) + 2H_{2}(g) → CH_{4}(g) ΔH° = -74.6 kJ

Calculate the following quantities.

ΔS_{sys} = ___ J/K

ΔS_{surr} = ___ J/K

ΔS_{univ} = ___ J/K

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Second and Third Laws of Thermodynamics concept. If you need more Second and Third Laws of Thermodynamics practice, you can also practice Second and Third Laws of Thermodynamics practice problems.