# Problem: For each of the following reactions, calculate ΔH°rxn, ΔS°rxn, and ΔG°rxn at 25 °C. State whether or not the reaction is spontaneous. If the reaction is not spontaneous, would a change in temperature make it spontaneous? If so, should the temperature be raised or lowered from 25 ∘C?Part A 2 CH4(g)→C2H6(g) +H2(g) Express your answer to one decimal place.ΔH°rxn = kJPart B Calculate ΔS°rxn at 25 °C. Express your answer to one decimal place.ΔS°rxn = J/K

###### FREE Expert Solution

We’re being asked to determine the standard enthalpy change (ΔH˚rxn) for the balanced reaction:

2 CH4(g)→C2H6(g) +H2(g)

Recall that ΔH˚rxn can be calculated from the enthalpy of formation (ΔH˚f) of the reactants and products involved:

The ΔH˚f values: can be found in books or online:

ΔH˚f CH4(g) = −74.81 kJ/mol
ΔH˚f C2H6(g) = −84.68 kJ/mol
ΔH˚f H2(g) 0 kJ/mol (ΔH˚f = 0 for elements in their standard state)

93% (134 ratings) ###### Problem Details

For each of the following reactions, calculate ΔH°rxn, ΔS°rxn, and ΔG°rxn at 25 °C. State whether or not the reaction is spontaneous. If the reaction is not spontaneous, would a change in temperature make it spontaneous? If so, should the temperature be raised or lowered from 25 ∘C?

Part A 2 CH4(g)→C2H6(g) +H2(g) Express your answer to one decimal place.

ΔH°rxn = kJ

Part B Calculate ΔS°rxn at 25 °C. Express your answer to one decimal place.

ΔS°rxn = J/K