A1.0 m h2s solution has a ph = 3.75 at equilibrium. what is the value of ka? 3.16 × 10−21 3.16 × 10−8 8.89 × 10−5 8.89 × 10−8

The answer is 3.16*10-8

You use the atomic number to find out how many protons and neutrons there are in the atom. you use the atomic mass to find out how many protons and electrons there are in the atom.