Answer to Question #223635 in Physical Chemistry for Raa

Question

To calculate the entropy change of the system for the combustion of one mole of methane gas at 298K. Standard entropies at 298K are as follows:

S⁰(CO₂)=213.7JK⁻¹

S⁰(H₂O)=69.9JK⁻¹

S⁰(CH₄)=186.3JK⁻¹

S⁰(O₂)=205.1JK⁻¹

Also calculate the entropy change of surroundings if the molar enthalpy of combustion of methane is -8.9×10⁵Jmol⁻¹

Answer 1

CH₄ + 2O₂ → CO₂ + 2H₂O

$∆H = 186.3+2(205.1)+213.7+2(69.9)=950 Jk^{-1}$