Question

Calculate the value of ΔG°, ΔH°, & ΔS° for the oxidation of solid elemental sulfur to gaseous sulfur trioxide at at 25°C. ​2S (s, rhombic) + 3O2( g) → 2SO3 (g)

Answer 1

2S (s, rhombic) + 3O2( g) → 2SO3 (g)

Standard Values for H⁰

S(s, rhombic) -----> 0 kJ mol-1

O₂ (g) ------> 0 kJ mol-1

SO_{3 (g)} ------> -395.2 kJ mol-1

Standard Values for G⁰

S(s, rhombic) -----> 0 kJ mol-1

O₂ (g) ------> 0 kJ mol-1

SO_{3 (g)} ------> -370.4 kJ mol-1

Standard Values for S⁰

S(s, rhombic) -----> 31.88 kJ mol-1

O₂ (g) ------> 205 kJ mol-1

SO_{3 (g)} ------> 256.2 kJ mol-1

Delta G⁰ of the reaction = G⁰ products - G⁰ reactants

= -370.4 - (0+0)

= -370.4 kJ mol-1

Delta H⁰ of the reaction = H⁰ products - H⁰ reactants

= [2 * (-395.2) ] - (0+0)

= -790.4 kJ mol-1

Delta S⁰ of the reaction = S⁰ products - S⁰ reactants

= (2 * 256.2) - [(2 *31.88)+(3 *205)]

= - 166.36 kJ mol-1