Sulfuric acid is the principal acidic component of acid rain. The mean pH of rainfall in southern Norway in 2000 was 4.6. What concentration of H2S04 will produce this pH by the reaction H2S04 ~ H HS04

The problem here is that according to aufbau principle before 3d orbital 4s subshell comes.after filling 3p orbital with electrons you have 4 electrons left, you place two in 4s with opposite spin and the other two in 3d in any of its two orbitals of total five orbitals with the same spin.

Sorry i dont understand the question can you rephase it?

D. h2o + h2o > h3o + oh- confirmed.