Hydrogen sulfide is a weak acid whose first hydrogen ion is lost according to the following reaction: H2S+H2OH3O+ + HS Ka = 1.5 x 10-7 for the above

Hydrogen sulfide is a weak acid whose first hydrogen ion is lost according to the following reaction:  

H2S+H2O→H3O+ + HS− 

Ka = 1.5 x 10-7 for the above reaction. For a solution that is 0.5 M in ????2???? and 0.3 M in ????????− determine the hydronium ion concentration and the pH.