Calculate the pH and pOH of a hydrochloric acid solution prepared by dissolving 30.50-kg of hydrogen chloride gas in 806-L of water at SATP.

Answer 1

I would convert 30.50 kg to grams.
mols HCl = grams/molar mass
Then M = mols/L

Since HCl is 100% ionized, (H^+) = (HCl) and pH = -log(H^+)
Then pH + pOH = pKw = 14. Use this to calculate pOH.
Finally, pOH = -log(OH^-) and calculate OH^-.