Answer:
2.5*10^-8 for sea water, 3.16*10^-11 for milk of magnesium, and 790 times greater
Explanation:
We're trying to find the concentration of H+ in the solution using the pH, so
let's define pH first.
pH=-log(H+)
This equation can be re-written as
H+ = 10^(-pH), or H+ = 1/(10^pH)
The pH of sea water is 7.6, so the concentration of H+ in sea water is 10^(-7.6), which is about 2.5*10^-8
The pH of milk of magnesium is 10.5, so the concentration of H+ in milk of magnesium is 10^(-10.5), which is about 3.16*10^-11
To compare how much more the concentration of the hydrogen ion is, we just divide
(2.5*10^-8)/(3.16*10^-11) = 791, or 790 with sig figs.