The concentration of hydrogen sulfide, H2S, in hot springs is relatively high. This accounts for the rotten-egg smell around the "mud pots" in Yellowstone National Park. The solubility of hydrogen sulfide in water at 25 degrees Celsius is 0.0932 M at 1.00 atm. If the partial pressure of H2S at Yellowstone is 0.12 atm, calculate the molarity of H2S in the mud pots.

I have no clue what to do..please help!

Use Henry's Law.