Problem: For the reaction 2CH4(g)→C2H6(g)+2H2(g) calculate ΔG∘rxn at 25 °C.Express your answer using one decimal place.Standard Thermodynamic Quantities for Selected Substances at 25 °C   Substance      ΔH∘f(kJ/mol)      S∘(J/mol⋅K)      CH4(g)   −74.6   186.3   C2H6(g)   −84.68   229.2   H2(g)   0   130.7   N2(g)   0   191.6   NH3(g)   −45.9   192.8   N2H4(g)   95.4   238.5   NO(g)   91.3   210.8   O2(g)   0   205.2   KCl(s)   −436.5   82.6   KClO3(s)   −397.7   143.1

FREE Expert Solution

$\boxed{\mathbf{\Delta G}{\mathbf{°}}_{\mathbf{rxn}}\mathbf{=}\mathbf{\Delta H}{\mathbf{°}}_{\mathbf{rxn}}\mathbf{-}\mathbf{T\Delta S}{\mathbf{°}}_{\mathbf{rxn}}}$

For this problem, we need to do the following steps:

Step 1: Calculate ΔH˚_rxn.

Step 2: Calculate ΔS˚_rxn.

Step 3: Use ΔH˚_rxn and ΔS˚_rxn to calculate for ΔG˚_rxn.