Question

Please, I need help with my homework!

Consider the reaction

2CO₂(g) + 5H₂(g)=C₂H₂(g) + 4H₂O(g)

for which ΔH° = 46.50 kJ and ΔS° = -124.8 J/K at 298.15 K.

(1) Calculate the entropy change of the UNIVERSE when 2.230 moles of CO₂(g) react under standard conditions at 298.15 K.

ΔS_universe _________ =  J/K

(2) Is this reaction reactant or product favored under standard conditions?

_________

(3) If the reaction is product favored, is it enthalpy favored, entropy favored, or favored by both enthalpy and entropy? If the reaction is reactant favored, choose 'reactant favored'.

_________​

Answer 1

(1) S_universe = -313.0 J/K

(2) Is this reaction reactant or product favored under standard conditions? : Reactant favored

(3) Reactant favored

Explanation

S_sys = (S^o) * (moles CO₂)

S_sys = (-124.8 J/K / 2 mol CO₂) * (2.230 mol CO₂)

S_sys = -139.152 J/K

H^o_sys = 46.50 x 10³ J

H^o_surr = -(H^o_sys)

H^o_surr = -(46.50 x 10³ J)

H^o_surr = -46.50 x 10³ J

H_surr = (H^o_surr) * (moles CO₂)

H_surr = (-46.50 x 10³ J / 2 mol CO₂) * (2.230 mol CO₂)

H_surr = -51847.5 J

S_surr = (H_surr) / (T)

S_surr = (-51847.5 J) / (298.15 K)

S_surr = -173.90 J/K

S_universe = S_sys + S_surr

S_universe = (-139.152 J/K) + (-173.90 J/K)

S_universe = -313.0 J/K