6. (10 The pH of a particular wastewater after traversing a 1.5-mile force main (wastewater is pumped through a closed conduit rather than flowing via gravity in an open channel) was 6.1 and the total sulfide concentration (sum of the sulfide in H2S and HS') was 100 ppmm. At pH 6.1 the sulfide species are in a molar ratio such that [H2S] = 10[HS]. This wastewater discharges into another lift station where a vapor phase of total pressure 0.91 atm is present. Determine the concentration of hydrogen sulfide gas (H2S(g) in ppm, that would be in this vapor if it were in equilibrium with the aqueous solution.