Question

Hydrogen sulfide is a pollutant found in natural gas. Following its removal, it is converted to sulfur by the reaction 2H2S(g)+SO2(g)⇌3/8S8(s,rhombic)+2H2O(l). What is the equilibrium constant for this reaction? Is the reaction endothermic or exothermic?

a) The equilibrium constant cannot be determined.
b) The equilibrium constant is 1.
c) The equilibrium constant is greater than 1.
d) The reaction is endothermic.

Answer 1

The equilibrium constant for the reaction involving hydrogen sulfide and sulfur dioxide cannot be determined without equilibrium concentrations. The reaction is similar to the exothermic reaction of sulfur dioxide to sulfur trioxide.

Step-by-step explanation:

The equilibrium constant for the reaction 2H2S(g) + SO2(g) ⇌ 3/8S8(s, rhombic) + 2H2O(l) cannot be determined directly from the information provided. To find the equilibrium constant (K), the concentrations or partial pressures of the reactants and products at equilibrium are needed.

As for whether the reaction is endothermic or exothermic, this is determined by the nature of the heat transfer during the reaction. In general, if a reaction releases heat, it is considered exothermic. Conversely, if a reaction absorbs heat from the surroundings, it is endothermic. The conversion of hydrogen sulfide to sulfur is similar to the oxidation of sulfur dioxide to sulfur trioxide (2SO2(g) + O2(g) ⇌ 2SO3(g)), which is exothermic as it releases heat.