What is the ph of an aqueous solution that contains 2.7 x 10^20 h3o?

Asolution at 25 degrees celsius is 1.0 × 10–5 m h3o+. what is the concentration of oh– in this solution?

Which statement best describes the oxidation numbers of the atoms found in magnesium chloride? a. magnesium has a 2- oxidation number and chlorine has a 1+ oxidation number. b. magnesium has a 2- oxidation number and chlorine has a 2+ oxidation number. c. magnesium has a 2+ oxidation number and chlorine has a 1- oxidation number. d. magnesium has a 1+ oxidation number and chlorine has a 1- oxidation number.

What is the number of moles of chemical units represented by 9.03x10^24? and how do i show work? (dumb it down )