A hazardous waste contains a lot of nickel (Ni2+). The EPA limit for nickel in water is 100 ?g/L (=100 x 10-6 g/L). What pH is required to meet the EPA limit? The Ks is 5.54 x 10-16 and Ni2+ = 58.7 g/mol.

1) For the Ni2+, convert 100 ?g/L to mol/L.
2) Using Ks and [Ni2+], solve for [OH-]
3) What is the pOH and pH